A Swedish appeals court has ruled to uphold the European arrest warrant for Wikileaks founder Julian Assange.

The decision maintains the legal demand for the 45-year-old Australian - who has sought refuge in the Ecuadorian embassy in London for four years - to be extradited to Sweden over rape allegations.

"The Court of Appeal shares the assessment of the District Court that Julian Assange is still suspected on probable cause of rape," the court said, adding that it had seen no new information to justify setting the case aside.

Assange, who denies the allegations, filed the appeal request after a UN panel said in February his presence at the embassy amounted to arbitrary detention.

The panel said Assange should be allowed to leave and should also be awarded compensation after a six-year legal stand-off.

Assange said he fears further extradition to the United States, where a criminal investigation into the activities of Wikileaks is ongoing.