A UKIP MEP and general election candidate has been suspended "following allegations of a serious financial nature", the party says.
Janice Atkinson, MEP for the South East, was due to fight the Folkestone and Hythe seat on 7 May.
She was suspended following a Sun newspaper investigation into potential impropriety by a member of her staff, relating to an expenses claim.
Ms Atkinson has not responded to BBC requests for comment.
Speaking to BBC Radio Kent, party leader Nigel Farage told the BBC a disciplinary hearing would be held "early next week".
He said: "It looks very bad - it couldn't look worse and I'm astonished by it."
'Couldn't believe it'
The newspaper has published a secret recording appearing to show Janice Atkinson's chief of staff, Christine Hewitt, speaking to the manager of a restaurant in Margate, Kent, before UKIP's spring conference.
In the footage, she appears to ask for an invoice for a much higher sum than the bill she had originally received.
Ms Hewitt is heard to say: "The idea is we overcharge them slightly, because that's the way we repatriate it."
A member of the hotel staff replies: "3,150, is that alright? Yeah, if you're alright with that? Is that enough for you?"
Ms Hewitt then says: "Oh God yeah, that's more than enough."
It is not known whether Ms Atkinson knew or authorised her staff member's apparent actions.
The BBC has been unable to contact Ms Hewitt for comment.
Mr Farage said it was too early to say whether Ms Atkinson would be allowed to run for UKIP in Folkestone and Hythe.
He said: "I spoke to her after midnight and she said it was all to do with bills and fundraising - I was frankly confused by it all."
He added: "I simply couldn't believe it - how on earth could anyone think they could behave like this."
A UKIP spokesman said the party was "incredibly disappointed" with Ms Atkinson, who appeared to have "exercised extremely poor judgement" and to "have acted in a way the party has never and would never condone".
Kent Police said it had not received any reports relating to the newspaper's allegations.
Last summer, Ms Atkinson caused controversy in Kent when she referred to a Thai constituent as a "ting tong".
The BBC's political correspondent, Chris Mason, said Ms Atkinson was not the first UKIP MEP to give the party a headache.
Two former UKIP MEPs have served jail terms and three have defected to the Conservatives in the last four years.
Earlier this week, members of the Scottish Parliament unanimously condemned remarks made by UKIP MEP David Coburn, after he compared a Scottish government minister, Humza Yousaf, to Abu Hamza.
Abu Hamza is serving life in the US for terrorism offences.
The suspension of Ms Atkinson leaves UKIP with headlines it could do without, our correspondent added.
'Dirty, nasty election'
Folkestone and Hythe is seen as a safe Conservative seat.
It was represented by former Home Secretary and ex-Conservative Party leader Michael Howard, from 1983 to 2010, when he stood down as an MP ahead of the last general election.
Fellow Conservative Damian Collins won the seat in 2010.
Ms Atkinson's suspension came shortly after Mr Farage had warned 2015 would be a "very dirty, nasty" general election campaign and urged his party to "turn the other cheek".
He had been speaking in Rochester where he welcomed two former Conservative Medway councillors, Tom Mason and Vaughan Hewett, who are standing for UKIP in the local elections in May.