Romania received “millions of dollars” from the CIA to allow the agency to torture terrorism suspects in secret prisons in the European country during the presidency of George W. Bush, says a human rights lawyer.

The claims were made by Amrit Singh during the opening day of a case at the European Court of Human Rights in Strasbourg, France, on Wednesday.

She noted that the prisons were operating in Romania from 2003-2005 with the government's "acquiescence and connivance."

Singh added that at a prison in Bucharest in 2004, her client, a Saudi national, was tortured by the CIA.

Abd al-Rahim al-Nashiri, currently in US custody at the Guantanamo Bay prison, was rectal-fed, sleep-deprived, and subjected to bright lights and loud noise during his imprisonment, she noted.

This December 2011 file photo shows the National Registry Office for Classified Information, also known as ORNISS, where the CIA operated a secret prison from the building's basement reportedly between 2003 and 2006, in a busy residential neighborhood minutes from the center of Romania's capital Bucharest. (AP)

The court announced that it would issue a ruling over the news in a few months to determine if Romania knowingly permitted the presence of the secret prisons where torture took place.

Amnesty International referred to the hearing, in which a similar case related to Lithuania was also presented, as a "milestone in accountability."

“Romania and Lithuania have never been held accountable for their direct involvement in CIA rendition and secret detention. Today’s hearing is a chance for the victims’ lawyers to set the facts out before the European Court in the hope that it will help break the conspiracy of silence,” said Julia Hall, Amnesty International’s expert on counterterrorism and human rights in Europe.

“The hearings today on the human rights violations in Romania and Lithuania are all the more important given that other avenues for accountability have been closed off to these victims of torture,” Hall added.

A 2014 report released by the US Senate Intelligence Committee detailed the torture tactics used by the CIA, including the extensive use of waterboarding.

The brutal practice, which mimics the sensation of drowning, was first allowed during George W. Bush’s administration for terror suspects.