Leading article: Only a proper investigation will suffice

The story we relate today regarding the behaviour of the British intelligence services, on the face of it, looks relatively benign. A Moroccan national was extracted by MI5 from a jail in Belgium. He subsequently agreed to work as a spy for the UK authorities, monitoring domestic extremist groups. There was no kidnapping and no torture. Indeed, the individual was facing deportation to Morocco, where he feared such barbaric mistreatment. But his removal from Belgium, if it occurred in the manner described, was nonetheless a breach of international law. No legal process was followed, and there were no safeguards. This might have been a consensual rendition; but it was rendition nonetheless.

And we need to remember some history. For a long time the previous Government flatly denied that the British intelligence services were involved in anything like this. In the words of the Foreign Office: "The UK's position on torture is clear. We abhor torture. We don't participate in, solicit, encourage or condone it. We unreservedly condemn any practice of extraordinary rendition for torture."

But in recent years cracks have begun to appear in this wall of denial. In 2008 it emerged that individuals had been transferred by the CIA through the British airbase at Diego Garcia, in the Indian Ocean. The then Foreign Secretary, David Miliband, was required to apologise for incorrect information given to MPs on this point.

Then came the publication of details from the disturbing case of the Ethiopian student and British resident, Binyam Mohamed. Mohamed was questioned by British intelligence officials in 2002 after being rendered from Pakistan to Morocco by the CIA. British officials did not kidnap Mohamed. They did not torture him. But his lawyers say they must have been aware that he was being mistreated in Moroccan custody. If that is true, the British intelligence services will be exposed as piggy-backing on the dirty work of others.

What is more, they frustrated efforts on the part of the legal authorities to discover the truth. Lord Neuberger, the top civil judge, who examined this Mohamed case, cast doubt on the veracity of the testimony he had received from the intelligence services. His verdict also left a question mark over the conduct of Mr Miliband (who tried to suppress a court document showing the involvement of MI5 in the Mohamed case). And now it would appear that there exists a British rendition programme – that our intelligence services are not only a passive player in the shady world of transporting individuals secretly across national boundaries, but an active one too. We urgently need to get to the bottom of all this; to discover exactly what our intelligence services have been doing in the so-called "war on terror".

Last month the coalition Government announced a judicial inquiry into the activities of the intelligence services since 2001. Yet this is to be chaired by the retired judge Sir Peter Gibson, who, as the Intelligence Services Commissioner, already oversees this sector and who has publicly praised all those who work for these services as "trustworthy, conscientious and dependable". The conflict of interest is glaring. An inquiry chaired by such an individual can have no credibility.

We need a debate on the methods used to thwart international terrorism. A plausible case can be made for the kind of rendition which this Moroccan national underwent. In some respects it is similar to the Cold War practice of "turning" a foreign intelligence agent. It is, however, much harder to make the case for allowing the intelligence services to kidnap individuals and deliver them up for mistreatment in repressive regimes. But first we need to find out what has been going on. The sad lesson of recent years is that we cannot rely on our elected politicians to tell us the truth. To get that, we need a rigorous and fully independent inquiry.