LONDON (Reuters) - Britain has extradited to the United States a mentally ill man alleged to be a lieutenant of Abu Hamza, a London imam convicted of terrorism charges in New York in May, police said on Tuesday.

Haroon Aswat, 40, a British citizen of Indian descent from Dewsbury, West Yorkshire, is wanted in the United States for allegedly conspiring with Hamza to establish a militant training camp in the state of Oregon in 1999.

He was originally arrested in Zambia in 2005 and deported to Britain where he was detained on arrival following a request from the U.S. for his extradition.

But in 2008 he was transferred from prison to Broadmoor, a high-security psychiatric hospital in southern England, where he was diagnosed with paranoid schizophrenia and has since been receiving treatment.

Last year, the European Court of Human Rights blocked his extradition because of his mental condition, saying his likely detention in a potentially “more hostile” environment could cause his mental and physical health to deteriorate.

Following assurances from the U.S., London’s High Court approved the extradition last month.

“Earlier today Aswat was taken from Broadmoor Hospital to a UK airport accompanied by ... extradition officers,” police said in a statement. “Officers were met at the airport by representatives from the US authorities who have escorted him on the flight to America.”

Abu Hamza, who was indicted in the United States in 2004 under his birth name, Mustafa Kamel Mustafa, spent eight years in prison in Britain for inciting violence before his extradition in 2012.