A former Romanian president has acknowledged approving the CIA's request for a site in Romania, but said he would have refused had he known how it would be used.

Ion Iliescu, president from 2000 to 2004, wrote on his blog on Monday that he believed Romania had hosted CIA "black sites'' where prisoners were held and subjected to torture.

Romanian authorities had long denied reports they hosted a CIA secret prison, but Iliescu said last week he approved a request for a site in 2002-2003. He was widely criticised for his remarks.

Iliescu wrote on this blog on Monday that "I would surely have taken another decision'' if he had known what the CIA was doing.

He did not mention the location of the site, its size or whether there was more than one.

The Associated Press news agency reported there were CIA black sites at a US airbase near the Black Sea port of Constanta and one in Bucharest. Romanian leaders have denied these reports.

Rights groups, European officials and media have reported there were also CIA sites in Poland and Lithuania.

Iliescu said Romania "assumed commitments.....in Romania's interests. For all of these there is a cost.''

Iliescu denied he had agreed to the CIA's request in exchange for getting US support for Romania joining NATO, which it did in 2004.

He said speculation that his recent comments served Russian interests was "ridiculous and degrading for Romania.''

Polish leaders also denied the existence of CIA sites until the US Senate' Intelligence Committee released a report in December on the CIA's practices.

Former Prime Minister Leszek Miller and former President Aleksander Kwasniewski admitted they had cooperated with US officials who needed a quiet location to question suspects.

They said that at the time they had no knowledge of abuse taking place there.