These reveal, shockingly, how the Labour government was happy for British nationals and residents seized in Afghanistan and Pakistan to be rendered to Guantánamo by the Bush administration, and how, in one case - that of Martin Mubanga, seized in Zambia - Tony Blair's office intervened to prevent attempts by the Foreign and Commonwealth Office to have him returned to the UK, leading to his imprisonment in Guantánamo for two years and nine months.

In paving the way for its announced inquiry into British complicity in torture, the coalition government attempted, without success, to persuade the High Court that, as the Guardian put it, "proceedings should be delayed while attempts at mediation are made" before the inquiry begins. Critics had already expressed their fears that the calls for "mediation" were a smokescreen for compensation deals that would attempt to buy the former prisoners' silence, so that the inquiry could proceed in secret without too many embarrassments.

Instead, however, the government's intervention has precipitously kick-started the inquiry in a very public manner, after Tim Otty QC, counsel for five of the men, said that proceedings "should be allowed to continue because the documents that the government is beginning to disclose shed new light upon the role that the UK authorities played in the men's mistreatment," and the judge, Mr. Justice Silber, agreed.

One of the most shocking documents disclosed in the High Court proceedings was issued by the FCO on January 10, 2002, the day before Guantánamo opened. Entitled, "Afghanistan UK Detainees," it described the government's "preferred options" in dealing with British prisoners. "Transfer of United Kingdom nationals held to a United States base in Guantánamo is the best way to meet our counter-terrorism objectives, to ensure they are securely held," the document explained, adding that the "only alternative" was to either hold these men in British custody in Afghanistan, or to return them to the UK.

In another shocking revelation, it was revealed that, in the case of Martin Mubanga, released documents "raise a number of troubling questions as to the role of the former Prime Minister's office in frustrating the release of one of the claimants," as Tim Otty described it, adding, "In the period of March and April 2002, the Prime Minister's office apparently countermanded a desire on the part of the Foreign and Commonwealth Office to intervene on behalf on Mr. Mubanga."

Mubanga, a joint British-Zambian national, had traveled from Pakistan to Zambia, where his sister lived, in February 2002, but had then been seized by the Zambian security services, and according to the documents released in court, the Prime Minister's Office had intervened to ensure that he was not brought back to the UK. As a result, the FCO was put in a difficult position: if officials sought consular access, thereby acknowledging British responsibility for him, he would have been released to the UK authorities, directly contradicting the Prime Minister's orders, which, as Reprieve noted yesterday, involved the Prime Minister "order[ing] the FCO to violate its international law obligations under the Vienna Convention, which requires the UK to provide consular assistance to British nationals around the world."

At the time, an FCO document complained about "the schizophrenic way in which policy on this whole case was handled in London," which had led to the British High Commission in Lusaka being placed "in an impossible position," and in an email dated August 22, 2002, an FCO official, recognizing that "we broke our policy" because of direct interference from Tony Blair's office, stated, "we are going to be open to charges of concealed extradition."

According to Mubanga, after the British finished with him - apparently having tried and failed to recruit him as a spy - the US agent who had been dealing with him told him, "I'm sorry to have to tell you this, as I think you're a decent guy, but in ten or 15 minutes we're going to the airport and they're taking you to Guantánamo Bay."

In court, Tim Otty highlighted Tony Blair's complicity in torture by pointing out that, by the spring of 2002, it was abundantly clear that there was a considerable risk that terror suspects in US control would be subjected to rendition and torture. "Despite that," he told the court, "someone at Number 10 saw fit to counter what the Foreign Office wished to do."

As the Guardian also explained yesterday, this was "not the only time the Prime Minister's Office intervened to thwart attempts by Foreign Office officials to obtain a degree of protection for British citizens." Minutes prepared for the Home Office Terrorism and Protection Unit after a meeting in April 2002 state that the US authorities "had been informed that the British government might begin making public requests for legal access to British men held at Guantánamo." According to the minutes, "FCO had wanted to do this (and wanted to be seen to be doing it) but had been overruled by No. 10."

The released documents also highlight the leading role played by Jack Straw, then the foreign secretary, in shaping the policies that led to the interrogations of British prisoners in US custody in Afghanistan, prior to their transfer to Guantánamo. As the Guardian explained, in mid-January 2002, Straw sent a telegram to several British diplomatic missions around the world in which he "signaled his agreement" with the Guantánamo policy, "but made clear that he did not wish to see the British nationals moved from Afghanistan before they could be interrogated." In the telegram, he wrote:

A specialist team is currently in Afghanistan seeking to interview any detainees with a UK connection to obtain information on their terrorist activities and connections. We therefore hope that all those detainees they wish to interview will remain in Afghanistan and will not be among the first groups to be transferred to Guantánamo. A week's delay should suffice. UK nationals should be transferred as soon as possible thereafter.

One of these "detainees" was Shaker Aamer, the last British resident still held in Guantánamo, and as a court heard in December last year, leading to the launch of a Metropolitan Police investigation, Mr. Aamer has claimed that British agents were present in the room, in the US prison at Kandahar airbase in Afghanistan, when he was subjected to abusive treatment by Americans.

Other interrogations revealed in the documents include those involving Omar Deghayes, seized from a house in Lahore in May 2002, who was treated disdainfully by the British agents who visited him, and an unidentified prisoner held in Kabul, under the heading, "Warriors 14/1," about whom the agents involved noted only, "Interview conditions: cold beaten up."

Extraordinarily, these documents are only the tip of a very murky iceberg, and it is unclear at present how many more will be publicly revealed. As has been previously reported, the government has identified up to 500,000 documents that may be relevant to the former prisoners' claim for damages, and, according to the Guardian, "says it has deployed 60 lawyers to scrutinize them, a process that it suggests could take until the end of the decade." In this first batch, "just 900 papers have been disclosed, and these have included batches of press cuttings and copies of government reports that were published several years ago," but as they also include these damning insights into the activities of Tony Blair, Jack Straw and the agents who interrogated British prisoners in appalling conditions, it is surely inconceivable that the government will now be able to conduct a secret inquiry into British complicity in torture, and must, instead, order a full and open inquiry.

This could take place under the Inquiries Act of 2005, like the Baha Mousa inquiry (into the murder, in British custody, of a hotel clerk in Iraq), which, as Reprieve noted when David Cameron announced the torture inquiry two weeks ago, was held under the Act and has been "a model of an inquiry functioning efficiently, including the hearing of secret evidence," and has also allowed for document classification review proceedings that "are sophisticated and rightly allow the judge to balance the need for national security against the need for transparency."

The time for silence, and the time for secrecy are over. To clear the air, and to draw a line under this most lamentable period in our recent history, we need an inquiry presided over by someone who is able to "balance the need for national security against the need for transparency." For too long now - and with baleful results - the need for national security has been allowed to override everything else, inflicting grave damage on our claims to be a civilized country, and leading to devastating effects for those caught up in a "War on Terror" with few checks and balances.

Note: To see the released documents in full, please visit the website of Reprieve, the London-based legal action charity whose lawyers represent dozens of current and former Guantánamo prisoners. The documents have also been made available by the Guardian. Please also note that, as well as Martin Mubanga and Omar Deghayes, the former prisoners involved in the civil claim are Binyam Mohamed, Bisher al-Rawi, Jamil El-Banna and Richard Belmar.