By Tony Grew - 6th December 2010
A Lib Dem MP has challenged the security services to prove the case against his researcher, who was arrested last week on the orders of MI5.
Mike Hancock said he has "no reason" to believe that Katia Zatuliveter, his parliamentary assistant, has been spying for the Russians.
She was arrested on Thursday and subsequently served with a deportation order.
The Sunday Times (£) quoted a source in the security services who said her presence was not "conducive to national security".
Ms Zatuliveter has worked for Hancock in the House of Commons since 2008.
She has been questioned several times since the summer about allegations of espionage.
The MP for Portsmouth South and a member of the defence select committee, Hancock is viewed as one of the most pro-Russian politicians in the House.
Yesterday he told Sky News that Zatuliveter had acted "honourably during the time she was working for me".
"She is determined to fight her corner and she genuinely believes, and I back her 100 per cent, that she has nothing to hide and has done nothing wrong," he said.
"If she has, the services are right. But they need to prove their point now."
Shadow foreign secretary Yvette Cooper and former foreign office minister Kim Howells have raised questions about the vetting of parliamentary researchers.
"I think the foreign office and intelligence services are acutely aware of this threat and I think they are going to be looking at making more funding available for the security services to tackle this kind of threat," Howells told BBC Radio 4.