John Whittingdale, the Culture Secretary, has made a dramatic statement admitting he had a relationship with a prostitute.

Responding to reports on the internet over recent weeks, he said it lasted six months but he ended it when he found out someone was trying to sell the story to newspapers.

It happened more than two years ago, he said, ,when he was chairman of the culture, media and sport select committee of MPs and before he joined the Cabinet last year.

Mr Whittingdale, 56, who has been an MP since 1992, married in 1990 and has two adult children but is now divorced. He was formerly political secretary to Margaret Thatcher and is now campaigning for Britain to leave the EU.

In his statement, the Culture Secretary said: “Between August 2013 and February 2014, I had a relationship with someone who I first met through Match.com. She was a similar age and lived close to me,” he said.

“At no time did she give me any indication of her real occupation and I only discovered this when I was made aware that someone was trying to sell a story about me to tabloid newspapers. As soon as I discovered, I ended the relationship.

“This is an old story which was a bit embarrassing at the time. The events occurred long before I took up my present position and it has never had any influence on the decisions I have made as Culture Secretary.”

There was no official response to Mr Whittingdale’s statement from 10 Downing Street, but Sky News understands the view in No. 10 is that he is a single man entitled to a private life and he has the full confidence of the Prime Minister.

The story first appeared online on 1 April and it is understood that it was investigated by a number of national newspapers but until Mr Whittingdale issued his statement they decided not to run it.

It was reported that Mr Whittingdale attended the MTV awards in Amsterdam with the woman but did not declare it in the Register of MPs’ interests. He says that was because it came under the threshold for declarations.

Responding to Mr Whittingdale’s statement, Labour’s Shadow Commons Leader Chris Bryant, who was shadow culture secretary until September last year, said: “It seems the press were quite deliberately holding a sword of Damocles over John Whittingdale.

“He has a perfect right to a private life but as soon as he knew this he should have withdrawn from all regulation of the press.”

Mr Bryant said that the Prime Minister had promised to fully implement the recommendation of the Leveson Inquiry into press standards, adding: “That’s what he should deliver.”

Brian Cathcart, the founder of the campaign Hacked Off, has claimed there was a conspiracy by the newspapers to cover up aspects of Mr Whittingdale’s private life because he is responsible for regulating the media.

Mr Cathcart also said Mr Whittingdale was guilty of a conflict of interest and should have told David Cameron about the relationship when he was appointed to the Cabinet in May last year.

But Tom Newton-Dunn, political editor of The Sun, told Sky News: “We didn’t publish the story because, quite frankly, there is no story.

“He is a single man, a divorced man – you can pretty much have a relationship with anyone you want.

“It gets complicated when you introduce the conspiracy theory.

“He is Culture Secretary… and he presides over media regulation and the reason why the media has not been touching story (according to conspiracy theorists) is because we are all too terrified to publish nasty stories about him because he will pass nasty laws against us.

“Quite frankly, that is rot.”