An investigation has been launched into how leading Palestinian activist Sheikh Raed Salah managed to get into the UK despite being banned, Home Secretary Theresa May has announced.
Mr Salah, the leader of the Islamic Movement in Israel, was detained late on Tuesday night in London by police, the Palestine Solidarity Campaign (PSC) said.
Mrs May said officials from the UK Border Agency were now taking steps to remove him from the country, adding: "We do not normally comment on individual cases but in this case I think it is important to do so.
"I can confirm he was excluded and that he managed to enter the UK. He has now been detained and the UK Border Agency is now making arrangements to remove him. A full investigation is now taking place into how he was able to enter."
Sarah Colborne, PSC director, insisted that Mr Salah was the leader of a legitimate political organisation and that he rejected all forms of racism, including anti-semitism.
A statement from his solicitor Farooq Bajwa added that Mr Salah had "no knowledge" of an alleged travel ban and had made "no attempt" to conceal his identity when he entered Britain.
"Sheikh Raed Salah is the leader of the Islamic Movement in Israel, the largest movement for Palestinians in Israel," Ms Colborne said. "This is a legitimate organisation which Israel has never moved to ban.
"Before coming to Britain, he faced horrific allegations of anti-semitism, which he completely refuted.
"He has clarified his position of being opposed to all forms of racism, including anti-semitism, Islamophobia and racism against his own people, the Palestinians."