Helena Kennedy: Intelligence alone cannot justify locking people up

It is hardly a triumph for democracy that a man spent 16 months in custody without being told why

On Thursday, the Court of Appeal upheld the decision of the Special Immigration Appeals Commission (SIAC) that the detention of M, a Libyan, was unlawful. The Home Office quickly placed a gloss on its defeat, claiming the result was proof that the system created for the internment of non-citizens was working. They point out that 12 of the Home Secretary's decisions to detain without trial have been endorsed by the SIAC; one of his decisions has been roundly criticised. Victory to the Home Secretary. In fact, all 12 are appealing to the Court of Appeal.

On Thursday, the Court of Appeal upheld the decision of the Special Immigration Appeals Commission (SIAC) that the detention of M, a Libyan, was unlawful. The Home Office quickly placed a gloss on its defeat, claiming the result was proof that the system created for the internment of non-citizens was working. They point out that 12 of the Home Secretary's decisions to detain without trial have been endorsed by the SIAC; one of his decisions has been roundly criticised. Victory to the Home Secretary. In fact, all 12 are appealing to the Court of Appeal.

It is hardly a triumph for democracy that a man spent 16 months in custody without being given the evidence on which the decision was based, but in the "war" against terror this will be described as collateral damage. For many, it seems reasonable; if there is intelligence available that people might be terrorists why not act sooner rather than later, since building a case against someone is time-consuming and resource-intensive and suspects may slip the net? Yet, it is important to consider what that intelligence is and the consequences of undermining fair trials.

There are three grounds for detention without trial under the Anti-Terrorism, Crime and Security Act 2001, quickly passed in the aftermath of 11 September. One: that a person is suspected of being involved in the preparation, commission or instigation of terrorist offences. Two: that a person is a member of a recognised terrorist organisation posing a threat to our security. Three: that a person has links with people or organisations believed to be terrorists or to have assisted in some way, such as financially. The overwhelming majority of those detained come under the third heading of having inchoate links with people or organisations. During the open part of the Court of Appeal hearing the Lord Chief Justice asked, "If I am a grocer and I supply goods to someone who might be al-Qa'ida, is that good enough?"

Those who are detained are not told on what intelligence the Home Secretary has based his decision. When he was explaining the absence of weapons of mass destruction, the Prime Minister recently agreed that there is no such thing as "hard intelligence" and he is right. Before 2001, intelligence was the starting point, triggering intensive police evidence-gathering to build a case. Not now.

In the detainee cases, the man's own lawyers are not given access to the intelligence. A special advocate who is security vetted sees it, but having done so he is not allowed to meet and speak with the detainee. M was lucky because, when the special advocate saw the quality of the intelligence in his case, it was manifest that his detention was based on the most tenuous of links. However, sometimes the best person to provide the basis for a challenge to ropy intelligence is the detainee himself.

If an informant has claimed that X was present at a meeting and declared support for al-Qa'ida, the detainee might be able to show that he has an alibi for the time in question or that the allegation cannot be true for other reasons. Two of the men who have been returned from Guantanamo confessed to having been in Afghanistan during particular events, but were subsequently shown to have been in Britain at the time.

The question we have to ask is how many of the other 12 remaining in custody would be released if they were able to answer the evidence on which the their detention is based.

The only way to counter international terrorism is through working across borders, and law has to develop synergies and systems to meet the new demands for collaboration. Nevertheless, we should be aware of some serious issues inherent in this move towards closer international collaboration of intelligence agencies and of closer links internally between the police and secret services.

Intelligence agencies operate in secret, at times they act outside the law and they give top priority to protecting their sources. The commingling of information sometimes makes it very difficult to evaluate its quality and origins. Information from foreign intelligence sources does not have the same assurances of reliability and accuracy. Torture is used. Hearsay is included. This is one of the reasons why the security services never want to go into the witness box and subject themselves to cross-examination and it is why we are abandoning proper trial processes in these cases.

We had to derogate from the Human Rights Act in order to put these new detention arrangements in place. We forgot that you do not defend democracy by undermining it.

The writer's latest book is 'Just Law' published by Chatto and Windus