Two presidents on from George W Bush, it may be hard to recall the transatlantic tensions that stemmed from the US prison camp at Guantanamo and the lengths to which UK governments went to secure the release of British citizens. How acutely sensitive the whole subject remains, however, has become apparent in recent days, as some of the prime decision-makers sought to justify themselves following the death of a former British detainee in an apparent suicide bombing in Iraq.

It is still not fully established that the man concerned really is Jamal al-Harith – once known as Ronald Fiddler – or precisely how he died. But the acute embarrassment caused by the subsequent activities of a former Guantanamo detainee – one of those for whose freedom UK ministers had pleaded – was plain for all to see. Not least because, it is claimed, he had received, if not actually £1m in compensation, then a pretty handsome settlement courtesy of UK taxpayers. So George W was right, the inference goes, and British ministers, yet again, were wrong.

You can understand why the politicians concerned might feel aggrieved to be thus charged, and so they did. First we had Tony Blair, prime minister at the time, say that he would not usually comment on retrospective criticism of his premiership, but that in this case the very same people now calling him soft on terrorism – the Daily Mail – had then been lobbying hard for UK detainees’ release.

Blair was followed by his then-Home Secretary, David Blunkett, in print and on the BBC, who had once upon a time given a pledge that no returned detainee would pose any threat to the UK. Yes, he had given such a pledge, he said, which was designed to reassure(!) the British public. And anyway, as it turned out, he added, Harith had indeed posed no threat to the British public.

Both also went to some lengths to dissociate themselves from the money. Blunkett alluded to the services of “greedy lawyers” in an effort to explain why – even if it was a million, and he wasn’t saying it was – Harith probably received considerably less. Blair, for his part, said the settlement was nothing to do with him; the money had been agreed by the Coalition government in 2010.

Guantanamo release: Former Afghan detainees' families relieved

Nor was this the end. The questions now came from Yvette Cooper, chair of the Home Affairs Committee, who wanted to know how much money there really was, what had happened to it, whether any of it had made its way to Isis, and whether any attempt had been made to reclaim it.

This last question had a nice touch of the absurd. After all, if the authorities had lost track of Harith to the point where he was able to leave for the Middle East untracked, why would they know where the money had gone, let alone have the capacity to recover any of it?

As the answers from a hapless Ben Wallace, minister for national security, inadvertently showed, however, the real nub of the Harith case – and of many others – should be sought elsewhere. The question is less “How much money was paid, to whom, and when?” than “Why?”

Why was the British government – of whatever complexion, in whatever year – paying cash compensation to former Guantanamo detainees? After all, if anyone was liable for what had happened to these men, surely it was the US administration? And if the US refused – as it consistently did – to pay even a cent, why was the British government such a pushover?

It is in the answers to this question that the real scandal lies, at least so far as the UK is concerned, and that scandal goes far beyond Harith and his fellow British detainees. A clue, but only a clue, is to be found in Wallace’s non-answer to the compensation question. Unlike former home secretaries, he said, he could not comment, because the Government was bound by the confidential terms of the settlement.

Again, what he does not say is why; why was everything kept under wraps? The truth is that the compensation paid to Harith and others was less in respect of any injustice or deprivation they had suffered than to keep the whole matter out of court. And in whose interests was it to keep it out of court? Not Harith’s, to be sure. The purpose was to conceal any involvement by the UK security services. And anyone who protests that there was no such involvement needs to ask why the government of the day judged that it was worth a million, give or take, to pre-empt a lawsuit that would be heard in open court. The sums had to be high enough to buy the victim’s silence. They were tantamount to hush money.

Nor is this an isolated instance. It is not only Harith who was denied his day in court. All Guantanamo-related cases have been settled at the taxpayer’s expense – to the detriment not just of transparency, but of justice. Indeed, almost any case where intelligence information is germane has been hampered to a greater or lesser degree by the protection afforded by the government to the intelligence services.

Before the inquest into the 7/7 London bombings, the presiding judge, Lady Justice Hallett, fought a battle royal to get even some intelligence evidence heard. The nine-year delay before the inquest/inquiry was held into the radiation death of Alexander Litvinenko was largely caused by repeated objections from the intelligence services. In the end, some intelligence evidence was heard, but only by the presiding judge in camera, on condition that it was excluded from his judgment. What quality of justice is this, where perhaps the most pertinent evidence is stifled?

It so happens that a new test of relations between the courts and the intelligence services is imminent. As Ben Wallace noted, while answering Yvette Cooper’s Commons questions, the Coalition government changed the law to allow intelligence evidence to be heard by a court in private – precisely in the hope of forestalling compensation awards such as Harith’s.

The case in question - two parallel cases in fact - concerns Abdel Hakim Belhadj, a prominent opponent of the Gaddafi regime, who, with his family, was abducted back to Libya from exile in an operation reportedly masterminded by MI6. Rather than settle for compensation, Belhadj chose to pursue a civil claim through the courts. Meanwhile, a criminal investigation mouned by Scotland Yard appeared to have come to an end last summer, when the Crown Prosecution Service decided not to bring charges against a former senior MI6 officer. Both cases remain live, with Belhadj having launched a judicial review the CPS's decision earlier this month. His lawyers may now apply to see classified documents related to the case.