A 28-year-old white British male is in custody after being arrested on Saturday.
Assistant Chief Constable Matt Longman provided additional details on the investigation at a press briefing on Sunday (12 July) morning, telling media the arrest took place in Rotherham.
There is still "nothing to suggest" it is a terrorism related or politically motivated crime, he added. "And at this point, we are not looking for anyone else in connection with this murder."
ACC Longman also said more than 120 tips from the public have been received since a police appeal for information.
Ms Widdecombe was found dead at her home in Haytor, on the edge of Dartmoor, at around 11.40am on Thursday.
Police believe the former Conservative minister was attacked at around 12.30pm on Wednesday - nearly 24 hours before her body was discovered with "serious injuries".
Devon and Cornwall Police said: "We can confirm that a 28-year-old man was arrested at an address in the South Yorkshire area this evening (July 11) on suspicion of the murder of Ann Widdecombe.
"The suspect, who is a white British national, is now in police custody."
The force said that it was supported by Counter Terrorism Policing North East, while South Yorkshire Police carried out the arrest, but added there is "still no information to suggest that this is a terrorism-related incident".
A 26-year-old man initially arrested by the force on suspicion of the murder of Ms Widdecombe was released from custody on Saturday, with police stating that he was no longer part of their investigation.
Ms Widdecombe served as a Conservative MP from 1987 to 2010.
She then returned to frontline politics as a prominent voice in the Vote Leave campaign ahead of the 2016 EU referendum, before joining the Brexit Party in 2019, serving as a Member of the European Parliament.
Ms Widdecombe joined Reform UK in 2023, and became the party's immigration and justice spokesperson.
Reform MPs given extra security
Nigel Farage visited Devon to lay a wreath for Ms Widdecombe on Saturday as it was confirmed Reform MPs have been given 24-hour security, paid for by the party, for fear of similar attacks.
Mr Farage said in a tribute on Friday that Ms Widdecombe's death was "a terrible reflection on modern Britain".
"And I do fear that for anybody in public life, or especially the political space, things have become even more dangerous to them," he added.
Widdecombe's missed TV appearance
As the police piece together the timeline of Ms Widdecombe's death, it was revealed that the former MP had missed a planned TV interview on Wednesday afternoon.
She had appeared on Mark Dolan's TalkTV programme earlier in the day, and was due to feature on Matt Allwright's Channel 5 show.
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WhatsApp messages published by ITV appear to show Ms Widdecombe stopped responding to messages from a producer on the programme around the time police believe the attack took place.
She last sent a message at 12.19pm, acknowledging she had received a Zoom link, but did not respond when she was asked to join the call at 12.48pm.
They were trying to help two children who had got into difficulty, Cleveland Police said.
Both children are safe and have been taken to hospital to be checked over.
Police were called to the scene at around 3.45pm on Sunday and officers attended with the RNLI, Coastguard and North East Ambulance Service medics.
The two men were brought out of the water by the RNLI and were given medical treatment but were pronounced dead a short time later.
Superintendent Glen Ward said: "Our deepest sympathies go out to the families of both the men involved in this tragic incident today.
"Despite the best efforts of emergency services, sadly both men were pronounced dead a short time after being brought out of the sea.
"We are conducting enquiries into the circumstances of what happened today, although the deaths are not being treated as suspicious and a file will be prepared for the coroner.
"I would like to remind everyone that open water comes with serious risks. We know it is inviting in the hot weather, but we would encourage people to refrain from entering any open water at all. Today we have sadly seen the true tragedy that can happen as a result.
"Please take extra care and enjoy the warm weather as safely as possible."
They are the latest in a spate of open water deaths this summer during successive heatwaves.
During the May heatwave, at least 15 people, mostly children, drowned while swimming in open water.
On Friday, two 18-year-old men died in separate incidents at Dovestone Reservoir, Oldham, and the Darley Abbey Mills complex, in Derbyshire.
Amber alerts issued by the UK Health Security Agency (UKHSA) for the West Midlands and South West, and yellow alerts for the East Midlands, the North West, the South East, the East of England and London, are in place until 9pm Wednesday.
The UKHSA said significant impacts are likely across health and social care services and warned of a potential increase in water-related incidents across England, including risks from risks from cold water shock and drowning.
Firefighters say they are working to protect communities from the fire near Sychnant Pass on Conwy Mountain.
The news comes with a huge swathe of the UK is at risk of "exceptional" wildfires in the coming week, according to Natural England.
See the weather forecast for your area
Dave Swallow, the National Fire Chief's Council's wildfire tactical advisor, told Sky News firefighters are currently tackling 19 wildfires across England and Wales and said strong winds following the prolonged dry weather are "exacerbating the challenge".
Jami Jennings, from North Wales Fire and Rescue Service, said: "Firefighters remain on scene working in challenging conditions to contain the fire and protect surrounding communities, property, infrastructure and the environment...
"Due to the size and complexity of the incident, operations are expected to continue for some time.
"We would ask members of the public to avoid the affected area to allow emergency services to work safely and efficiently. Please follow any road closures, evacuation advice or safety instructions issued by the emergency services.
"Residents in nearby communities of Dwygyfylchi and Penmaenmawr should keep windows and doors closed if affected by smoke and seek medical advice if they experience breathing difficulties. Motorists are advised to expect delays and consider alternative routes."
North Wales Police are overseeing the evacuation residents living nearby.
There is concern about the heatwave leading to wildfires elsewhere in the country.
The Fire Severity Index (FSI) measures how severe a blaze could be, going from level one (low) to level five (exceptional).
The forecast for the coming days shows the likely fire severity is "very high" across most of England - and by Thursday (16 July), a huge swathe of the country will be in the top category.
Information on wind speed, temperature, time of year and rainfall is used to produce the forecasts, along with weather data from the Met Office.
Derbyshire Fire and Rescue has been called out to two moorland wildfires in recent days, while some London rail lines were closed on Friday evening after a blaze involving shrubbery at Stratford station.
On Saturday, teams tackled a fire at Devil's Dyke in South Downs National Park, West Sussex, and firefighters in East Sussex were called out to a "large fire in the open" on the South Downs near Eastbourne.
The scorching heatwave conditions being experienced by much of the UK are due to last into the coming week, with most areas expected to stay dry, sunny and very hot.
Mr Swallow warned that such conditions "significantly increase wildfire risk" but said almost all are started by people - either deliberately or accidentally.
"Whether it is a disposable barbecue left behind, a discarded cigarette, or even a glass bottle left in the sunshine, we all have a role to play in preventing them," he said.
Heat-health alerts issued by the UK Health Security Agency (UKHSA) were extended on Saturday.
Amber alerts for the West Midlands and South West, and yellow alerts for the East Midlands, the North West, the South East, the East of England and London, will remain in place until 9pm Wednesday.
The UKHSA said significant impacts are likely across health and social care services, and warned of a potential increase in water-related incidents across England, including cold water shock and drowning.
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Wildfires have raged across southern Europe in the past week.
Firefighters in southeastern Spain are still battling a blaze that started on Thursday - which has so far killed 12 people, with a further 23 missing - while several wildfires are ongoing amid soaring temperatures in France, where a firefighter has died.
The contest between Sinner and Zverev was closely fought, with the first two sets finishing 6-7 and 7-6, respectively.
It stayed tight at the start of the third set, but Sinner came through to claim it 6-3. At one point, Zverev threw his racket down in frustration.
Sinner's victory follows his 2025 championship win, making him the tenth Wimbledon men's singles champion to retain the title in the open era.
The 24-year-old Italian achieved the feat with a fourth-set 6-4 victory. Speaking on centre court following his win, he said: "My mum had to leave the stadium a couple of times! It was an amazing final. It takes two players.
"We tried to give everything we have, I'm happy about thew win, but I'm also happy about the level we both played at.
"There is no better place to play tennis, honestly. I could feel the nerves when I woke up, and this is a very, very special day. I never take it for granted."
Zverev was also coming off a strong year, having claimed his first grand slam title at his fourth attempt at a major final in June, winning the French Open over 14th-ranked Flavio Cobolli.
Speaking about his rival, Sinner said: "It's amazing. To Alex - he got his first Grand Slam in Paris this year, and he was so, so close today.
"If he keeps playing like this, I am sure he will have this Wimbledon trophy soon.
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Last week, the 29-year-old German beat British wildcard Arthur Fery - who enjoyed a dream run that saw took close to being only the second Briton to reach a men's singles Wimbledon final in the open era.
Speaking to the Prince and Princess of Wales at Wimbledon today, Fery invited Prince George and Princess Charlotte to play tennis with him.
The royals also congratulated the British player - who turns 24 today - on his run to the semi-finals and wished him a happy birthday.
Emergency crews were called to a property in Uxbridge Road, Hayes, shortly before 8am on Sunday.
They found the woman with stab wounds who died at the scene.
The man, aged in his 20s, was found outside the property with stab injuries. His condition is unknown.
The Metropolitan Police said officers "quickly located" a 44-year-old man matching the suspect's description nearby.
He was arrested on suspicion of murder and possession of a bladed article in a public place. The suspect was taken to hospital with injuries believed to have been caused from jumping from a window.
Detective Chief Inspector Allam Bhangoo said: "This is a shocking incident which has tragically resulted in one woman losing her life and another man in hospital with injuries."
The senior officer added that police inquiries were in the early stages but detectives "do not believe there to be any wider threat to the public".
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A large area around the property was behind a police cordon on Sunday afternoon, with a dozen police officers on site.
A tent was set up next to a car on Uxbridge Road, while forensic officers carried out searches and reviewed documents nearby.
A 67-year-old woman who lives nearby said: "It's scary what happened, and it's scary seeing the police, tent and everything.
"I've lived here for 12 years and I've never seen anything like it. It's safe usually, I feel safe."