Assange on the cover of the New York Post. (AP)

Stockholm/London, Dec. 2 (Reuters): Swedish police said today that technical problems hindering the arrest of Julian Assange, the founder of whistleblowing website WikiLeaks, had been overcome, and a British newspaper said he was in Britain.

A Swedish court upheld an arrest order for the 39-year-old Australian for alleged sexual crimes, refusing to let him appeal a lower court’s ruling. He denies the allegations.

A spokesman for WikiLeaks said Assange had received assassination threats and had to remain out of the public eye.

The Swedish legal case against Assange has rumbled on since September, while WikiLeaks has leaked a mass of material which has angered the US and embarrassed some of its allies.

The Independent newspaper said Assange had arrived in Britain in October, and had given police his contact details. It cited police sources who said they knew where Assange was staying. He was believed to be in southeast England, it said.

WikiLeaks spokesman Kristinn Hrafnsson, speaking at an event in London last night, said Assange was working on the project at a secret location.

In Sweden, Assange’s efforts to have an arrest order quashed met defeat when the High Court declined to hear the case.

“The High Court has not granted a leave to appeal, so the Svea Court of Appeals ruling still stands,” High Court official Kerstin Norman told Reuters. The Svea court of appeals is one of six courts of appeal and covers the Stockholm area. Tommy Kangasvieri, head of the international unit at the Swedish National Police force, said the problem over the arrest warrant had been solved.

“We have sorted this out and it will be completed during the day,” he said, adding that Swedish police had not received any official word that Assange was in Britain.