Nigel Farage said an incident at his London home last year was "directly linked" to the murder of Ann Widdecombe, after counter-terror police reopened an inquiry into it last week.

It relates to what Farage described as a "lit incendiary device" being pushed through his letterbox in April 2025, the BBC understands.

Counter Terrorism Policing (CTP) London has also referred itself to the police watchdog over how the initial investigation was handled.

At a Monday press conference, the Reform UK leader said: "I understand this is a completely unprecedented move, and yes, this is directly linked to the murder of Ann Widdecombe, and I'm afraid I just can't tell you any more than that at this stage."

Asked about the investigation, he said: "Clearly, counter-terrorism made some mistakes, which is why they referred themselves to the Independent Office of Police (Conduct)."

It is not yet clear how the incident at Farage's house is linked to Widdecombe's murder.

Police said at the time that "damage was caused to a door but nothing was stolen".

Both CTP London and the Metropolitan Police were involved in enquiries. No arrests were made and the investigation was closed.

But on Friday, CTP London said a new line of inquiry had been identified that was not "pursued by them at the time".

The Independent Office for Police Conduct (IOPC) said it had "decided to independently investigate the conduct of a Counter Terrorism Policing London staff member following a referral received earlier [on Friday]".

A statement continued: "The conduct relates to an allegation the individual failed to identify and pursue a line of enquiry relating to an attempted burglary reported in April 2025."

CTP London said it would fully engage with the watchdog's investigation, and that the "victims and families in both investigations have been updated".

Ann Widdecombe, the 78-year-old former Conservative minister and Reform UK spokeswoman, was found dead at her home in Devon last month with serious injuries.

Joshua Kerry, from Rotherham in South Yorkshire, was later charged with her murder.

Kerry was initially arrested on suspicion of murder on 11 July, before being additionally arrested on 13 July on suspicion of the commission, preparation or instigation of acts of terrorism.

Widdecombe had served as Tory MP for Maidstone in Kent for 23 years and was appointed to ministerial roles in Sir John Major's government in the 1990s.