By Steve Swann
BBC home affairs correspondent
Ethiopian asylum seeker Binyam Mohamed recently returned to Britain
Lawyers for seven men who were detained at Guantanamo Bay are seeking a court order preventing any evidence of their alleged mistreatment being destroyed.
The UK citizens and residents claim the British government and security service colluded in acts including rendition, unlawful detention and torture.
The men say papers which may back their damages claims could be destroyed.
The government said it supported transparency when releasing documents "where possible".
Each of the seven men was arrested under suspicion of terrorism and eventually transferred to the US naval facility at Guantanamo Bay in Cuba where they say they were mistreated.
None was ever charged and all now live freely in this country.
One of the group - the Ethiopian asylum seeker Binyam Mohamed - claims he was interrogated by American officials about information that could only have come from British sources.
The Metropolitan Police is investigating whether to bring charges against the MI5 officer who worked on his case.
Another of the former detainees, Omar Deghayes, was held in Cuba for five years.
He says he was repeatedly interrogated about a scuba-diving course he attended in Brighton and a video filmed in Chechnya, which he was wrongly accused of appearing in.
He believes both allegations came from the British security services.
Speaking to the BBC, he described Guantanamo Bay as "a very black page in [American] history. Everyone involved will regret it."
The Foreign Office has insisted the government does not condone or practise torture.
It said the prime minister has told MPs he will "publish the guidance given to our intelligence officers and service personnel about the standards that we apply during the detention and interviewing of detainees overseas".
That would take place after the guidance had been reviewed by the Intelligence and Security Committee of MPs and peers, the Foreign Office statement added.
But lawyers for the seven men say they are so concerned about the potential for papers to go missing, that they will ask for an independent supervisory solicitor to be appointed to oversee the retrieval of documents.
The application will be made in the High Court on Wednesday - the same day another legal attempt is made by Binyam Mohamed's lawyers to seek the publication of information on his case.
The significance of documentation has also been highlighted in the United States.
Former Vice President Dick Cheney has called for the release of papers showing how harsh interrogation can yield important information.
This was in response to President Barack Obama's publication of memos outlining the legal justification for techniques such as water-boarding.
The interrogation technique involves a prisoner having a cloth pushed into his mouth and having water poured on to his face.