Britain is condemned today in a highly critical UN report for breaching basic human rights and "trying to conceal illegal acts" in the fight against terrorism.

The report is sharply critical of British co-operation in the transfer of detainees to places where they are likely to be tortured as part of the US rendition programme. It accuses British ­intelligence officers of interviewing detainees held ­incommunicado in Pakistan in ­"so-called safe houses where they were being tortured".

It adds that Britain, and a number of other countries, sent interrogators to Guantánamo Bay in a further example of what "can be reasonably understood as implicitly condoning" torture and ill-treatment. It said the US was able to create its system for moving terror suspects around foreign jails only with the support of its allies.

Some individuals faced "prolonged and secret detention" and practices that breached bans on torture and other forms of ill-treatment, the report says.

The document, drawn up for the UN general assembly by Martin Scheinen, the organisation's special rapporteur on the "promotion and protection of human rights and fundamental freedoms while countering terrorism", is likely to add pressure on the government, which is facing demands from human rights groups and frontbench opposition MPs for an inquiry into the role of UK security and intelligence officials in the CIA's secret transfer of detainees to "dark prisons".

The UN report comes days after fresh ­disclosures about MI5 co-operation in the secret interrogation and torture of ­Binyam Mohamed, the UK resident recently released from Guantánamo Bay.

While the practice of extraordinary rendition was put in place by the US, it was only possible through collaboration from other countries, the report says. It identifies the UK, with ­Bosnia and Herzegovina, Canada, Croatia, ­Georgia, Indonesia, Kenya, Macedonia and Pakistan, as countries that provided "intelligence or have conducted the initial seizure of an individual before he was transferred to (mostly unacknowledged) detention centres in Afghanistan, Egypt, Ethiopia, Jordan, Pakistan, Morocco, Saudi Arabia, Yemen, Syria, Thailand, Uzbekistan … or to one of the CIA covert detention centres, often referred to as 'black sites'".

The report continues: "The active or passive participation by states in the interrogation of persons held by another state constitutes an internationally wrongful act if the state knew or ought to have known that the person was facing a real risk of torture or other prohibited treatment."

It highlights concerns about "the increasing use of state secrecy provisions" and accuses the UK, along with the US, Germany, Italy, Poland, Romania and the former Yugoslav republic of Macedonia, of concealing "illegal acts from oversight bodies or judicial authorities".

The report says information that is inaccurate and wrongly recorded can lead to innocent people being identified as terrorist threats, referring to Bisher al-Rawi, a British resident seized in Gambia after MI5 tipped off the CIA.