Devon and Cornwall Police said in a statement posted on Facebook that the suspect was arrested at an address in the South Yorkshire area on Saturday evening (July 11).
"We can confirm that a 28-year-old man was arrested at an address in the South Yorkshire area this evening on suspicion of the murder of Ann Widdecombe," the police said.
The suspect, identified as a white British national, remains in police custody, police added, confirming that Widdecombe's family had been informed about the development.
However, authorities clarified that there was no indication so far that the incident was linked to terrorism.
"This is a live and active investigation, and no further information will be issued tonight," police said.
Earlier, police had confirmed that a 26-year-old man who was initially arrested in connection with Widdecombe's death had been released and was no longer part of the investigation.
A murder investigation was launched after the former MP was found dead at her home on Dartmoor in Devon on July 9. Detectives from the Force Major Crime Investigation Team are leading the probe and carrying out extensive inquiries into the circumstances surrounding her death.
Detective Chief Inspector Ilona Rosson described the incident as "extremely tragic" and said the investigation was progressing rapidly.
"Our thoughts are very much with the family and friends of Ann Widdecombe at this difficult time," Rosson said.
Who was Ann Widdecombe?
Ann Widdecombe was a veteran Conservative Party politician who served as the Member of Parliament for Maidstone and later Maidstone and The Weald from 1987 to 2010.
After leaving the House of Commons, she remained active in public life through television and radio appearances. She returned to politics in 2019 as the Brexit Party's lead candidate for South West England in the European Parliament election, winning a seat and serving as a Member of the European Parliament until the UK's exit from the European Union in January 2020.
Widdecombe later joined Reform UK in 2023 and served as the party's Immigration and Justice spokesperson until her death.
Beyond politics, she was also known for her television appearances, including competing in the eighth series of Strictly Come Dancing in 2010 and finishing as runner-up in the 21st series of Celebrity Big Brother in 2018.
She contested the Plymouth Sutton and Devonport seat in the December 2019 general election as a Brexit Party candidate, finishing third.