An American court's decision to allow its intelligence agencies to withhold evidence about Britain's involvement in "extraordinary rendition" promotes impunity for any UK officials complicit in such operations, a senior United Nations representative said last night.
The UN Special Rapporteur on human rights and counter-terrorism, Ben Emmerson, said that the controversial ruling had been reached "on dubious legal grounds" and warned it would hamper efforts to establish the truth of what British officials and ministers knew about the controversial practice.
The Independent reported this week that a judge in Washington DC had allowed the agencies, including the CIA, the FBI and the National Security Agency, not to supply crucial documents to British parliamentarians.
The MPs are investigating the extent of British complicity in rendition – the practice of arresting terrorist suspects and flying them to other countries to be tortured. The claims have been given extra impetus by accusations uncovered by The Independent that British agents were behind the rendition of a critic of Muammar Gaddafi to Libya, where he was tortured.
Mr Emmerson said the ruling "flies in the face of principles of best practice for the oversight of intelligence services".
"Refusing disclosure of key information about the alleged participation of UK officials in extraordinary rendition runs the risk of promoting impunity for state officials of the UK who may have been party to grave human rights violations," Mr Emmerson said at a public hearing of the European Parliament.
"Transparency is key not only to bring to justice those officials who may have participated in crimes of this kind but also in dispelling unjustified suspicions. The unjustified maintenance of secrecy, on dubious legal grounds, only delays efforts at establishing the truth."
MPs and peers on the All-Party Parliamentary Group on Extraordinary Rendition have made more than 40 requests in 2008 for files under freedom of information legislation.
British police are investigating the claims by Abdelhakim Belhaj that UK officials conspired to send him back to the Gaddafi regime. Detectives are expected to interview Jack Straw, who was Foreign Secretary at the time. He denies any complicity in rendition.