Bucharest (AFP) - Romania is "ready to clear up" allegations that the country hosted secret CIA detention centres, the foreign ministry said Tuesday -- though it stressed that Bucharest had "no proof" such prisons existed.

Romanian authorities were "fully available to clear up the allegations" that Bucharest colluded with the CIA on the transfer of terrorist suspects to CIA "black sites" established for the purposes of torture, the ministry said.

The ministry emphasised in a statement that the central European country was not named in the summary of last week's bombshell US Senate report on the CIA's mistreatment of Al-Qaeda suspects.

In fact, however, the summary redacted the names of all foreign countries that hosted the CIA "black sites" used to intern 119 people who were captured.

But previous news reports identified the countries which had the sites as Romania, Poland, Lithuania, Thailand and Afghanistan.

The Romanian foreign ministry said an investigation had been launched with a view to finding "a solution" to the issue that "respects the principles of the rule of law and human rights".

The public prosecutor's office told AFP a probe had been launched following a complaint from Abd al-Rahim al-Nashiri, one of the suspects named in the US Senate report as a torture victim.

The prosecutors gave no further details.

Al-Nashiri's name features in the Senate report alongside with those of three other suspected al-Qaeda members held at Guantanamo Bay, whom the report said had been tortured.

The 49-year-old Saudi is accused of masterminding the suicide bombing of the USS Cole in Yemen in 2000 in which 17 American sailors were killed.

In May 2012, he filed a criminal complaint in Romania, claiming he had been secretly detained in the country between 2003 and 2006.

He has also taken a case at the European Court for Human Rights.

Romania has never admitted to hosting secret CIA prisons.

Its foreign ministry reiterated Tuesday that Bucharest possessed "no proof of the existence of CIA detention centres in Romania or the use of Romanian airports for the transport or detention of prisoners suspected of terrorist acts".

A former head of Romania's intelligence service, Ioan Talpes, said Saturday the CIA may have kept detainees in a "transit" centre in Romania but that Bucharest was unaware of the activities conducted at the site.

Mediafax agency said Talpes had been questioned by prosecutors in 2013 in connection with al-Nashiri's case.