A deputy police and crime commissioner has resigned following allegations that he deceived a 19-year-old woman political activist into forming a sexual relationship while working as an undercover police officer in the 1990s.

Andy Coles, who was Cambridgeshire's deputy police and crime commissioner, tendered his resignation on Monday following news reports.

In a statement, Mr Coles said: 'There have been news reports over the weekend about which I am unable to comment. This coverage is significantly impacting on my ability to carry out my duties as deputy police and crime commissioner.

'I have therefore today tendered my resignation with immediate effect, which police and crime commissioner, Jason Ablewhite, has accepted. I am aware that the allegations have been referred directly to the Independent Police Complaints Commission (IPCC).'

The allegations were referred to the IPCC by the Cambridgeshire Police and Crime Panel.

Cambridgeshire police and crime commissioner Jason Ablewhite said: 'Following news reports over the weekend, deputy police and crime commissioner, Andy Coles has taken the decision to resign from his post with immediate effect. I have accepted his resignation.

'The matter has been referred directly to the Independent Police Complaints Commission (IPCC) for their consideration, therefore I will not make any further comment.' Cambridgeshire Police and Crime Panel also said it could not comment. A page on the commissioner's website, detailing his deputy's biography, is no longer available.

Mr Coles was revealed to have been a member of a Metropolitan police undercover unit which monitored political activists.

After leaving the police, in 2012, he became a Conservative councillor for Fletton, on Peterborough City Council. Last year, he was appointed deputy police and crime commissioner.

In a blog he said at the time: 'After a long career in London as a Scotland Yard detective, I know that crime and disorder can quickly make our homes feel unsafe. I am pleased to be able to use my policing knowledge to support the police and crime commissioner in his work in supporting our constabulary to improve and to challenge performance where necessary.'