EU governments should apologise collectively for continuing to turn a blind eye to CIA rendition sites on their soil, according to a key European Parliament committee.

Speaking after the Parliament's Justice and Civil Liberties committee backed her report by 50 votes to 2 with 5 abstentions earlier this week, Helene Flautre, a French Green MEP, criticised governments for having "not properly fulfilled their obligation under international law to investigate serious human rights violations connected with the CIA programme".

The CIA's extraordinary rendition programme, where terrorist suspects were transferred by plane to secret detention centre, was launched by the Bush administration as part of the "war on terror" following the September 11 attacks. Over 1,000 CIA flights are estimated to have used European airspace between 2001 and 2005.

Eleven EU countries - Germany, Sweden, Spain, Ireland, Greece, Cyprus, Denmark, Romania, Italy, Poland, Portugal and Britain - have faced allegations of involvement in extraordinary renditions and secret detention centres used by the US intelligence service.

MEPs are critical that no action has been taken by the European Commission and Council, representing member states, to determine the involvement of member states.

"Despite a huge amount of evidence on illegal detention and rendition most national governments have failed to follow up and there has been a kind of omerta in Council on it," said a spokesman for the Green group.

Meanwhile, Dutch Liberal MEP Sophie In't Veld described the EU's silence as a "disgrace", adding that "Europe loses credibility and moral authority unless it comes clean about its own role in the CIA renditions and black site programme".

The report, which comes five years after the assembly's temporary committee on extraordinary rendition adopted its first report by Italian socialist Claudio Fava, highlights new revelations of human rights violations and the complicity of EU governments with the CIA.

Among its recommendations, the report called on Romania and Poland to launch independent inquiries into alleged CIA detentions on their territory, but welcomed suggestions that Lithuanian government authorities were prepared to re-open investigations.

A report by the Lithuanian parliamentary committee on two detention sites led an MEP delegation to visit the country in April 2012.

Finland, Denmark and Portugal were also asked to "disclose all necessary information on all suspect planes associated with the CIA and their territory." The report, which is not legally binding, will be debated and voted on by MEPs in Strasbourg in September.

As expected, MEPs representing countries subject to allegations came under domestic pressure to water down the report.

A senior Parliament source claimed that the Romania delegations had been among those tabling multiple amendments "seeking to dumb down sections dealing with abuses in their countries", although Flautre praised MEPs for having "stood firm and voted in favour of the report" despite coming up against "considerable pressure from national interests seeking to keep a lid on these allegations".

The Parliament report built on conclusions reached in an internal paper published in June by the Parliament's policy department challenged the legitimacy of the internal inquiries organised by member states.

In all cases, member state governments denied any involvement, before setting up internal parliamentary inquiries or judicial inquiries conducted by the state judiciary. While no inquiry has yet implicated a member state, the report insisted that the procedures had "accountability challenges which taint the clearance, impartiality and objectivity of the final results".

It added that "politics and state secrecy playing fundamental roles in preventing disclose of the truth and access to justice".