Image copyright Other Image caption Roger Bird and Natasha Bolter

The general secretary of UKIP has denied a claim that he sexually harassed a newly-recruited candidate.

Roger Bird has been suspended from his post on full pay over what the party called "allegations of impropriety".

Natasha Bolter, 35, who used to campaign for the Labour Party, has told the Times Mr Bird propositioned her over dinner on the day he interviewed her as a prospective candidate.

She denies claims by Mr Bird they had a sexual relationship.

As a Labour activist who had switched to Nigel Farage's party, Ms Bolter, a teacher, was greeted by cheers and applause when she addressed UKIP's conference in Doncaster in September.

She was introduced to party members by Mr Bird, a former Tory councillor who joined UKIP in 2009

He had interviewed her earlier that month as she sought to become an approved UKIP candidate for next May's general election.

Speaking to the BBC, Mr Bird said they had a sexual relationship. But in her comments to the Times, Ms Bolter denies this.

Mr Bird told the BBC: "We were in a relationship briefly, but that relationship developed well after she had been admitted to the approved candidates list, so her selection was not connected to that."

A UKIP spokesman confirmed that an investigation had been launched.

On Monday, the party said it had acted "swiftly and decisively" as soon as it became aware of the allegations.

But it declined to discuss the nature of the claims, saying it was an "internal party matter".

A statement on its website said: "Unfortunately, UKIP has had to suspend Mr Bird pending a full investigation into allegations made against him.

"The party has acted swiftly and decisively and will not tolerate impropriety of any kind amongst its staff."​​

It is understood that an internal party disciplinary committee will decide what to do about the claims before Christmas.

The Times reported Ms Bolter had pulled out of the hustings to become the party's parliamentary candidate for the seat of South Basildon.

Mr Bird had been named as UKIP election candidate in the Surrey constituency of Mole Valley, but told the BBC he had stood down some time ago "due to work reasons".

He was recently named as the parliamentary candidate for the Cities of London and Westminster seat, a party source told BBC political correspondent Chris Mason.