Media playback is unsupported on your device Media caption Natasha Bolter tells Newsnight: "I know he is lying because I did not sleep with Roger Bird"

UKIP activist Natasha Bolter has said a senior party figure was "lying" when he said they had a relationship.

General Secretary Roger Bird has been suspended as UKIP considers a complaint relating to candidate selection.

Ms Bolter has accused Mr Bird, 41, of propositioning her on the day he oversaw her completion of an exam for prospective candidates.

Mr Bird denies that version of events, claiming that he had a "consensual relationship" with Ms Bolter.

He has released text messages which he says back up his case.

UKIP expect to hold a disciplinary hearing over the allegations of sexual harassment before Christmas.

'Thrown to wolves'

Asked by the BBC's Newsnight if she had a relationship with Mr Bird, Ms Bolter - a 35-year-old former Labour activist - said: "If I would have slept with him I would have probably have had an easier time than I have had in UKIP.

"It was almost... I joined the party and I was thrown to the wolves."

Pressed again by correspondent Tom Mangold as to whether she or Mr Bird is lying, she claimed: "I think he... I know he is lying because I did not sleep with Roger Bird. End of."

It emerged on Monday that Mr Bird, one of UKIP's most senior figures, had been suspended from his post on full pay over what the party called "allegations of impropriety" in relation to candidate selection.

Mr Bird has published texts and e-mails which he claims show he was in a consensual relationship with Ms Bolter between 18 September and 2 November, when he said he requested it should end.

Speaking to the BBC on Monday, Mr Bird claimed the two had had a sexual relationship.

"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," he said.

'Internal matter'

Mr Bird, a former Tory councillor who joined UKIP in 2009, introduced Ms Bolter when she spoke at the party's autumn conference in September.

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

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."​​

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

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.