A British MP has insisted a Russian woman who works for him has "nothing to hide" after she was arrested reportedly on suspicion of espionage.
Katia Zatuliveter faces deportation after being detained in London on Thursday in what is thought to be the first time since the end of the Cold War someone working in Britain's parliament has been accused of spying for Russia.
The 25-year-old was arrested after British domestic intelligence agency MI5 decided she was working for the Russian intelligence service as a "sleeper" agent, the Sunday Times reported.
Liberal Democrat MP Mike Hancock, who employed Zatuliveter in the House of Commons, dismissed the spying allegations and said she was planning an appeal.
"I have no evidence ... to support the view that she is any way a threat to the United Kingdom," he told the BBC.
The politician sits on a parliamentary committee tasked with overseeing the work of the Ministry of Defence and his constituency in Portsmouth, on England's south coast, has significant naval interests.
But he insisted that Zatuliveter, who has lived in Britain for almost three years, was not working on anything sensitive.
"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 told Sky News television.
She had already been questioned by the security services in August after being stopped as she returned to Britain, Hancock said in a statement.
The removal order came after Home Secretary Theresa May was briefed by MI5 on Zatuliveter, who was thought to be working for the SVR, Russia's foreign intelligence service, the Times said.
The SVR is the modern successor to the KGB and remains intensively active in the post-Cold War period.
A source cited by the paper said the Russian's presence was "not considered to be conducive to national security. There was unhappiness about what she could have access to. The intention is to show her the door".
The latest controversy over alleged Russian espionage comes after 10 sleeper agents were expelled from the United States in July.
If Zatuliveter were deported, it could place further strain on Britain's diplomatic relations with Russia, which are only just emerging from an icy period after the murder by poisoning of the dissident Russian spy Alexander Litvinenko in London in 2006.

25세 보좌관 간첩혐의 추방령
영국 보안당국이 의회 내에서 간첩 활동을 해온 혐의로 한 러시아 여성을 적발해 추방령을 내렸다고 영국 언론들이 5일 보도했다.
선 데이타임스는 이날 영국 국내정보국 MI5가 하원 국방특별위원회 마이크 행콕 자유민주당 의원의 보좌관으로 일해 온 카티아 자툴리베테르(25•사진)의 간첩 활동 행위를 적발했다고 보도했다. 영국 의회 내에서 러시아를 위한 간첩활동 혐의가 드러난 것은 냉전 종식 이후 처음 있는 일이다. 그는 러시아 대외정보국(SVR)을 위해 스파이 활동을 해온 것으로 전해졌다.
이 신문은 자툴리베테르가 러시아 문제에 깊은 관심을 보이고 있는 행콕 의원에게 처음부터 의도적으로 접근했다고 보도했다. 그는 지난주 경찰에 체포됐으며 본국 송환을 앞두고 영국 내 한 보안시설에 구금돼 있다. 자툴리베테르에 대한 추방령은 테레사 메이 영국 내무장관의 재가를 받은 것으로 알려졌다.
그러나 행콕 의원은 자신의 보좌관에 대한 이 같은 간첩 혐의를 부인하고 나섰다. 행콕 의원은 “자툴리베테르는 러시아 스파이가 아니며 이에 대해 아는 바가 없다”며 “그 역시 자기가 잘못한 것이 없다면서 추방 명령에 항소했다”고 말했다.
선데이타임스는 최근 몇 주간 행콕 의원실이 국방 문제와 관련된 많은 사안을 정부 측에 질문했는데 여기에는 영국이 보유한 핵무기 목록, 세계 각지의 잠수함 기지 위치 등도 포함돼 있었다고 보도했다.
영국 언론들은 이번 사건이 2006년 런던에서 전직 러시아 연방보안국(FSB) 요원 알렉산드르 리트비넨코가 암살된 이후 악화돼 온 양국의 외교관계를 더 경색시킬 수 있다고 우려했다.