WikiLeaks founder Julian Assange cited unclassified messages exchanged inside a UK intelligence agency to back his refusal to be extradited to Sweden. One of the messages calls sex-related allegations against Assange “a fit-up”.

The Australian, who has been stranded at Ecuadorian embassy in London for almost 12 months, cited instant messages he received from Government Communications Headquarters (GCHQ), the British signal intelligence body.

One message from September 2012, which Assange read out in a Sunday night interview with Spanish TV program Salvados, says: "They are trying to arrest him on suspicion of XYZ … It is definitely a fit-up… Their timings are too convenient right after Cablegate."

Another conversation he cited goes: "He reckons he will stay in the Ecuadorian embassy for six to 12 months when the charges against him will be dropped, but that is not really how it works now is it? He's a fool… Yeah… A highly optimistic fool."

Assange did not explain who the people exchanging the messages were, but said he managed to obtain them because they were not classified.

"[GCHQ] won't hand over any of the classified information," he said. "But, much to its surprise, it has some unclassified information on us."

GCHQ confirmed to RT that it released the info to Assange under the Data Protection Act. It can be used by individuals to obtain personal information that UK bodies have about them. The agency is exempt from the Freedom of Information Act, the usual mechanism for getting information of interest released by officials.

It stressed that the comments Assange received do not reflect GCHQ’s official stance in any way.

“As was made clear to Mr. Assange when the information was disclosed to him, the comments that he refers to in his recent interview were a small number of casual observations on a current affairs issue made by a handful of staff on GCHQ's internal informal communication channels. The comments were entirely unrelated to the individuals' official duties,” a spokesman for the agency said in an email.

A British court ordered that Assange be extradited to Sweden, where authorities want to question him on sex-related allegations. He refuses to go to there unless it guarantees that it won’t extradite him to the US, where he faces espionage charges over data released by WikiLeaks.

Ecuador has given Assange asylum and houses him in a small basement room in its London embassy. UK law enforcement keeps a close eye on the embassy, ready to arrest Assange should he leave the diplomatically-protected building.

The cost of the surveillance, which is believed to involve two police vehicles and eight officers on duty at all times, is now over $16,500 a day, Scotland Yard recently reported. The operation cost British taxpayers over $5 million since Assange got his refuge on June 19, 2012. By the time the anniversary falls, the sum is expected to have gone over $6.3 million.