The Rail Accident Investigation Branch (RAIB) revealed the finding in a statement on Wednesday.
The driver, who died at the scene, has been named as 60-year-old Shaun Burton.
Mr Burton died when the East Midlands Railway (EMR) train he was driving hit the back of a stationary train run by the same operator.
The RAIB said in an interim report that Mr Burton's train proceeded past a red signal near the scene of the crash in Elstow, near Bedford, at 5.15pm on Friday.
It said that "it is not yet possible to say what indication the driver received" from automatic warning system (AWS) equipment fitted to the train.
Some 162 people were injured in the crash, with 102 needing hospital treatment.
Fifty-three remain in hospital, including eight in a critical condition.
Images from a CCTV camera on Mr Burton's train show a signal near the scene of the crash "was displaying a red aspect as the train approached and then passed it", the RAIB said.
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Preliminary analysis of a recovered data recorder shows the train was travelling at 76mph when its brakes were applied nine seconds before the crash.
Its speed had reduced to 49mph by the moment of impact.
The stationary train involved in the crash had come to a halt "unexpectedly" after a fault with its AWS equipment caused its brakes to apply, the RAIB statement said.
This resulted in the signal behind it automatically switching to red, investigators added.
Approaching trains must stop at red signals.
The RAIB said its full investigation will consider "the actions of those involved and any factors that may have influenced them".
It will also look at the "positioning, visibility and conspicuity" of the signal that Mr Burton passed.
Will Rogers, managing director of EMR, said it would be "inappropriate" to comment on "specific findings" or speculate on the circumstances of the crash "before all of the evidence has been examined".
While Dave Calfe, general secretary of train drivers' union ASLEF, asked why a train protection and warning system (TPWS) had not been installed where the crash happened.
The technology automatically applies a train's brakes when it detects it will be unable to stop before a red signal.
"If it had been installed, this accident would not have happened, the driver would not have died, and no passengers would have been injured," Mr Calfe said.
Transport secretary Heidi Alexander said her "deepest sympathies" are with everyone affected by the "tragic collision", particularly Mr Burton's family and those who are still in hospital.
She continued: "The report makes clear there is still much to establish, and the full investigation will provide the answers and recommendations everyone affected deserves.
"Our railway is one of the safest in the world, and while incidents like this are incredibly rare, when they do occur we will leave no stone unturned to understand what happened."
No timeline has been given for when the investigation will come to a close.
Meanwhile, British Transport Police (BTP) has asked passengers who left items on board the two trains to provide information about them.
BTP said it had "carried out extensive searches of the affected trains and recovered a significant amount of passenger property".
The items have been moved to an EMR storage facility and passengers are asked to get in touch with their contact information and details of which items they left.
Joanne Penney, 40, died from a single bullet to the heart in March last year in Talbot Green, South Wales, as part of a dispute over drug dealing.
The killing was linked to a clash of rival gangs - Rico OCG, headed by Joshua Gordon, and another headed by Daniel "Jimmy" Joseph.
Gordon, 27, Renaldo Baptiste, 39, Marcus Huntley, 21, Kristina Ginova, 21, Melissa Quailey-Dashper, 40, and Jordan Mills-Smith, 33, were all convicted of murder and of gang offences.
Judge Mr Justice Fordham said Ms Penney was an "innocent victim of a drugs war... all she did was open her front door," and added the shooting was planned to be "a decisive show of strength" for the organised criminal group.
He explained that the doorstep shooting was plotted by the six as retaliation against Joseph, who had humiliated members of Rico when they were in the Talbot Green area.
Passing sentence, the judge said: "Joanne Penney was an innocent victim in a drug war. All she did was open a front door at a friend's house.
"A future taken away, an entire family shot through the heart when Joanne Penney, the mother, daughter and sister, loved by so many family and friends was so senselessly taken.
"No period of imprisonment can reflect the value of the life that was taken away by murdering her."
After the shooting, the judge noted that Gordon said Ms Penney's death was "a huge problem" for the Rico gang, and that Huntley tried to bury the firearm used, while Quailey-Dashper deleted messages.
"The purpose of the violent attack was to promote your illegal drugs trade, in aid of your criminal enterprise," he told Gordon, and addressing the group, he added: "It was about getting the upper hand."
Baptiste used hidden prison phone to supply gun
The court was told Rico OCG had been based in Leicester, but later branched out into South Wales.
Prosecutors said Huntley and Gordon's plan was to target "someone at the address" and that Ms Penney had not been singled out.
The court was told Quailey-Dashper knocked on the door of the flat - which was linked to drug dealing - while Huntley immediately shot the person who opened the door.
Jurors also heard Baptiste used a hidden phone while in prison to supply the gun that killed Ms Penney in Talbot Green.
Police found Ms Penney in the living room with a single gunshot wound to the chest. She was pronounced dead at the scene.
'Her loss has left an irreplaceable gap'
In a tribute released through South Wales Police, Ms Penney's family described her "kindness, strength and love for her family".
"Her loss has left an irreplaceable gap in our family," they added, "and the pain of losing her is something we will carry with us every day.
"Nothing can ever make up for what has been taken from us or bring Joanne back to those who loved her."
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Gang leader Gordon was sentenced to life with a minimum term of 32 years, along with a concurrent sentence of three years and 10 months for gang crimes.
Baptiste was sentenced to life with a minimum of 42 years for the murder and taking part in organised crime, which the judge noted was exacerbated by his previous convictions and his criminal history in prison.
The judge also handed Huntley a sentence of life with a minimum of 30 years and 146 days for the murder, and Mills-Smith was jailed for life with a minimum of 27 years.
Quailey-Dashper and Ginova were both given life sentences, with minimum terms of 14 and 12 years respectively.
Five other defendants, Sai Raj Manne, 26, Molly Cooper, 33, Callum Kelleher, 37, Laura John, 23, and Donna James, 51, are to be sentenced later for offences connected with the murder.
James Desborough, 40, is accused of the murder of Daniel Coleman, 43, and Claudio Aquilino, 57, last summer.
Opening the trial, lead prosecutor Ahmed Hossain KC told the jury at Winchester Crown Court that "dismembered" body parts of both victims were found by police in Paramoor Woods, near Sticker, Cornwall, during searches near Desborough's cabin.
Mr Hossain said: "In August, they [police] were searching in a stream that ran close to Mr Desborough's cabin. What they found were over 1,900 burnt bone fragments."
"The stream was divided into segments. The roots of plants had caught various fragments. All of those fragments were sieved, itemized and DNA analysis confirmed they had found what was left of Claudio Aquilino's body."
He said the second victim, Daniel Coleman, was found dismembered in a shallow grave.
The jury were shown a map of the woods.
"You can see torso, legs and feet", Mr Hossain said.
Mr Hossain said Desborough told a forensic biologist in the woods he "particularly enjoyed the dismemberment scenes" in the TV programme Dexter, about a police ballistics expert who lives a double life committing murders and disposing of the bodies around Miami.
The prosecutor added: "That is a series which involves scenes of dismemberment and disposal of bodies.
"There are many, many people who are fans of the television programme Dexter but, on the behalf of the prosecution, when you consider that comment by Mr Desborough together with the fact that two dismembered bodies were found on his land, that comment takes on a particular significance."
Mr Hossain also told jurors that Desborough went on to steal their money.
Mr Hossain said: "In 2025, James Desborough murdered Daniel Coleman and Claudio Aquilino.
"Parts of their dismembered bodies were found by police search teams and scientists when searching an area of woodland which was where James Desborough lived."
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He added: "Both of these men had lived with Mr Desborough...and these two men were last seen alive in the company of James Desborough.
"After each of them disappeared, their bank accounts were accessed and their money was spent by James Desborough.
"He killed them, he dismembered their bodies, he attempted to burn and bury their remains to conceal what he had done, and then used their money whilst at the same time lying to those around him about where they had gone."
Mr Hossain said Mr Coleman had lived with his wife, Hannah Cresswell, at Sandy Lodge shelter in Newquay until March 2025 when they split.
He added that Desborough had become involved in a relationship with Ms Cresswell which had led to arguments between the pair.
Mr Coleman was last seen alive on June 3 when he had been drinking at a number of pubs with the defendant in Truro and Falmouth, the prosecution said.
Desborough, of Lower Sticker, Cornwall, denies the charges. The trial continues.
A man has been arrested on suspicion of murder after the 26-year-old victim was found at Nine Ladies Stone Circle in Stanton Lees, Derbyshire, on Monday afternoon.
The discovery came after the celebration of the summer solstice, which falls on the longest day of the year, on Sunday.
The victim has not yet been formally identified.
The 41-year-old man who was arrested remained in custody on Wednesday.
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Detective Inspector Tony Owen from the East Midlands Special Operations Unit, who is leading the investigation, appealed for any witnesses who were at the solstice celebration between Friday and Tuesday to come forward.
He said: "I am urgently appealing for anyone who attended the summer solstice event over the weekend to please speak to officers as soon as they can.
"A young man's life has been taken in the most brutal way so it is vital that myself and the team build up a clear picture of the exact circumstances surrounding his death."
The stone circle is traditionally believed to depict nine ladies turned to stone as a penalty for dancing on a Sunday.
Det Insp Owen added: "We know that there have been a lot of people in the area of Nine Ladies Stone Circle over the weekend celebrating the summer solstice and this incident will undoubtedly be shocking and distressing to those who were present, as well as the wider community."
He also said that there will be increased police numbers at the site over the coming days and urged anyone with information to contact the officers.
Nine Ladies Stone Circle is part of a complex of prehistoric circles and standing stones on Stanton Moor.
Most of these are thought to date from the Bronze Age, around 3,000 to 4,000 years ago, according to the English Heritage website.
The former mayor of Greater Manchester is all but set to take over from Sir Keir Starmer as prime minister after Wes Streeting, his main leadership rival, dropped his candidacy and rowed in behind Mr Burnham following his by-election victory in Makerfield.
He was followed by Darren Jones, a Starmer loyalist, who confirmed to Sky News that he would not throw his hat in the ring to force a leadership contest, despite reports that the prime minister's allies had been encouraging him to.
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One Labour MP told Sky News: "Even where supportive of Andy, CLP [constituency Labour Party] members aren't keen on a coronation and favour a contest so they can see him put through his paces. There is a lot of concern that we haven't seen a plan yet."
Another, when asked if their local party members favoured a contest over a coronation, said: "Yes but what will be will be now. There is a general acceptance of a coronation now Darren has said he's not standing."
A third Labour MP added: "Most CLPs always want to feel a part of things, understandably - although often times it's the core group of activists rather than every member.
"No one wants a dictatorship but so few people actually vote so much of the time."
"The party and MPs need to be mindful now of ensuring people realise a coronation isn't a deliberate act if no one else wanted to stand. We don't want to alienate people."
They continued: "Perhaps Andy Burnham will do a 'tour' to bring the members with him. I hope he will."
Mr Burnham confirmed on Monday that he would stand to replace Sir Keir as Labour leader and prime minister after his victory over Reform in the Makerfield by-election saw him return to the Commons to take up his seat as a new MP.
In an interview with Beth Rigby on the Electoral Dysfunction podcast, Mr Jones said he had decided not to stand because he had received the assurances he was looking for from Mr Burnham regarding his plans for the economy.
"Well, look, I was never planning or organising a leadership campaign like some of my colleagues," he said.
"I was getting on with the job as chief secretary to the prime minister.
"And Andy Burnham is going to be the next prime minister. And if there was a contest of Labour Party members, he would win.
"So the question for me is, well, what would the benefit be to the country and to the party of a leadership contest?"
He added: "We talked then a lot about what he was thinking on the economy and what my thoughts were on that, and some of the potential ways forward for the new government."
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Although Mr Jones has ruled himself out of the contest, there are still questions over whether Al Carns, who resigned as armed forces minister over the defence investment plan, could throw his hat into the ring.
The Royal Marines officer Al Carns told journalists at the Foreign Press Association in London that he had not ruled out standing in a potential contest.
Nominations for the Labour leadership open on 9 July and close on 16 July, with a leader to be elected by 1 September if there is a contest.
On Tuesday, Downing Street confirmed that Sir Keir held face-to-face talks with Mr Burnham.
He has pledged to oversee a "smooth transition" of power following his resignation and has authorised Civil Service access talks to begin for "prospective candidates" for the Labour leadership.




