Sweden's military admitted Friday it inspected an alleged CIA plane that landed at a Stockholm airport in 2005, after an official report found no proof of CIA flights visiting Swedish airports since 2002.

"We inspected the plane but have no other comment," military spokesman Roger Magnergaard told daily Expressen, which reported the aircraft was being used for a covert prisoner transport.

Questioned by AFP, Magnergaard would only say that his comments to the newspaper "were correct."

The Swedish military's chief legal counsel, Stefan Ryding-Berg, later told AFP the military could not confirm the plane was used by the CIA, saying only that it was "a civilian airplane on a state mission."

Swedish authorities have only confirmed that one CIA plane landed at Stockholm's Bromma airport in December 2001, to transport two Egyptians expelled from Sweden to Egypt for their suspected involvement in an extremist organisation linked to the Al-Qaeda network.

That case caused an uproar in Sweden, after it was established that the pair were wrongly expelled and subjected to torture in Egypt. Sweden has paid both men more than 300,000 euros (dollars) in compensation, though one of them remains imprisoned in Egypt.

A government-ordered report conducted by Sweden's Civil Aviation Administration and the Civil Aviation Authority concluded in December 2005 that there was no proof that CIA planes had landed in Sweden after 2002.

The report, which studied 19,000 take-offs and landings in Sweden, came on the heels of intense media speculation that three planes possibly used by the CIA for covert prisoner transports may have landed in the country.

The report confirmed the three landings, but said there was no evidence the planes were used by the US intelligence agency.

But Expressen claimed Friday that in 2005 the Swedish military was ordered by the then-Social Democratic government to examine a plane at Stockholm's Arlanda airport that it suspected of covertly transporting prisoners.

Expressen said military investigators disguised as airport ground crew observed "a plane full of hooded prisoners in chains."

An unidentified source told the paper that Stockholm wanted proof of the covert transport in order to pressure Washington to stop using Sweden as a transit country.

The prime minister at the time, Goeran Persson, was not available Friday for comment.