Britain's Supreme Court has ruled that Julian Assange, the Australian founder of the controversial website WikiLeaks, can be extradited from Britain to Sweden to face charges of sex crimes.

Wednesday's decision by the high court upholds earlier decisions made by two lower courts to extradite the 40-year-old Assange, who is wanted in Sweden on a European arrest warrant after he was accused of raping one woman and sexually assaulting another in 2010. His lawyers say the warrant is invalid because the prosecutor who issued it had no legal authority to do so.

Assange, who has denied the charges, can make one last appeal to the European Court of Human Rights.

The WikiLeaks website gained international notoriety when it released hundreds of thousands of classified U.S. documents, including diplomatic cables held by the State Department about the wars in Iraq and Afghanistan.