Assange 'arrested by London police'

WikiLeaks founder Julian Assange has reportedly been arrested by British police over a sex crimes arrest warrant, as the net tightened around the website behind the release of secret US documents.

WikiLeaks founder Julian Assange has been arrested in London on suspicion of rape on an arrest warrant issued by Swedish authorities, British police say.

Assange, 39, was detained after attending a London police station by appointment at 9.30am (2030 AEDT) and is due to appear at City of Westminster Magistrates Court later in the day, the Metropolitan Police said in a statement.

"Officers from the Metropolitan Police Service's Extradition Unit have this morning, Tuesday 7 December, arrested Julian Assange on behalf of the Swedish authorities on suspicion of rape," the statement said.