SCOTLAND Yard said on Sunday that it was investigating a report alleging that MI5 and MI6 intelligence agents were complicit in the torture of British suspects both before and after September 11 2001.
The 55-page dossier contains evidence of abuse suffered by 29 detainees, including British citizens, with the knowledge of MI5 and MI6 officers abroad.
Police received the Fabricating Terrorism II report, compiled by lawyers acting for human rights group Cageprisoners, on Friday.
A Metropolitan Police spokesman said: "We have received a report and are considering its contents."
The study concludes: "The report has found systematic violations of international law perpetrated by the British authorities in relation to a) illegal rendition or torture flights which have been and are using British airspace and airport facilities.
"And b) the role of the intelligence services in gaining information knowingly obtained from torture, and from passing on intelligence of a dubious nature to other countries' intelligence services which forms a basis for the detention, abuse and torture of detainees."
The document includes evidence from Farid Hilali, a Moroccan man who had been living in Britain and was initially detained in 1999 in the United Arab Emirates.
He claims the British gave "direct orders" to torture him and that a British official was present when he was mistreated.
Baroness Scotland has already asked the Metropolitan Police to investigate former Guantanamo Bay detainee Binyam Mohamed's claims of "criminal wrongdoing."
Asim Qureshi, who produced the report for Cageprisoners, said it demonstrated that Mr Mohamed's treatment was not a one-off.
"They will look at all the cases and realise there is something more systematic taking place. We assume there is a policy involved. We're hoping Baroness Scotland will take up the issue," he said.