Devon and Cornwall police assistant chief constable Matt Longman said there was no information to suggest the murder was related to terrorism or had a political motive.
Widdecombe was well known for her socially conservative views, first as a junior minister in Conservative prime minister John Major's 1992-1997 government and latterly as an immigration and justice spokeswoman for Nigel Farage's populist Reform UK.
She also found fame outside politics after starring in TV shows Strictly Come Dancing and Celebrity Big Brother.
Police said officers were called to Widdecombe's home shortly after midday on Thursday, where she was found dead.
Forensic examinations at the property were ongoing, they said.
Prime Minister Keir Starmer paid tribute to "Ann's dedication during her many years of public service".
He said that it was a moment to "rise above any political differences" and added he had spoken to his expected successor Andy Burnham, Commons Speaker Lindsay Hoyle, Conservative leader Kemi Badenoch and Reform UK leader Farage about the case.
In one of her most memorable comments, Widdecombe said her former boss and future Conservative leader Michael Howard had "something of the night about him".
She later joined Farage's Brexit Party and served as a member of the European Parliament between 2019 and 2020.
Following the announcement of her death, and before details of the murder inquiry were announced, former colleagues from both the Conservative and Reform UK parties paid tribute to her.
Farage said she "played a decisive role in getting Brexit over the line".
Former Conservative prime minister Boris Johnson called her "a heroic Brexiteer and a great speaker who could move Tory audiences to such ecstasy that she was a very hard act to follow."
Widdecombe, who appeared on TalkTV on Wednesday, lived in Haytor, near Newton Abbott in Devon.
UK Home Secretary Shabana Mahmood urged the public not to speculate, describing the circumstances as "extremely distressing".
In a post on X, Mahmood said: "I am deeply saddened to hear of the death of Ann Widdecombe. The circumstances of her death are extremely distressing and my thoughts are with Ann's family and loved ones".
"I urge everyone to avoid speculation and allow the police investigation to progress."
with PA
7°C