In December 2005, Foreign Secretary Jack Straw told the Commons foreign affairs committee: "Unless we all start to believe in conspiracy theories and that the officials are lying, that I am lying ... that Secretary [of State Condoleezza] Rice is lying, there simply is no truth in the claims that the United Kingdom has been involved in rendition, full stop, because we have not been."
Ian Cobain's Cruel Britannia leaves no room for doubt that there was, simply, every truth in the claims and that it is beyond rational belief that Straw was unaware of this.
Guardian journalist Cobain has produced a book to send a shudder through even those disposed to believe the worst of Britain.
What he has dragged from the darkness into the light shows that the Pat Finucane affair was by no means a one-off and certainly not peculiar to Northern Ireland, but followed a pattern of torture, murder and lies, which had for decades been a weapon in the arsenal of British 'anti-terrorist' operations.
Along the way, incidents are recorded so startling as to require a second reading for confirmation. In Aden in 1966, members of the SAS (the SAS!) stopped handing captured suspects over to military intelligence, because of the severity of the torture they had witnessed.
One former SAS man is quoted on a particular incident: "Some members of B Squadron were restrained only with the greatest difficulty from shooting the interrogator."
Strategies for extracting information - or misinformation - from captured suspects go back at least to the Second World War.
Robert Buttler-Brandenfels, a Soviet agent in wartime Berlin, was picked up by the Gestapo in February 1943, tortured for two years and then sentenced to death.
He was released as the Red Army reached the gates of the city and made his way to the British zone where he offered to spy on the Soviets.
But the British believed he might be a plant. He was eventually sent to an interrogation centre in the village of Bad Nenndorf, near Hanover, where prisoners were subjected to ill-treatment which it is difficult to read of without retching.
Many were made to strip in the evening and buckets of sewerage dumped on their clothes. After a night in frozen cells, they were made to put on "wet, half-frozen and utterly disgusting rags".
After release, Buttler-Brandenfels had to have four toes amputated. "I had never in all those years [in the hands of the Gestapo] undergone such treatment."
Torture by military and civilian intelligence services (MI5, in particular, emerges as an organisation of either sadists, or psychopaths) was carried out with gusto in Kenya, Cyprus, Guyana, Swaziland, Malaya, Borneo, Aden and anywhere else a section of local people was seen as in rebellion against British interests. This didn't necessarily involve armed insurrection. In Swaziland, the targets were striking miners; in Guyana supporters of elected prime minister, Cheddie Jagan.
Any lingering restraint was sloughed off after 9/11. Cobain's account of the behaviour of the security services in the 'War on Terror' provides the most stomach-churning chapters in the book. No reader will come away believing any more the relentless assurances of British ministers that they didn't know of the evils being perpetrated in the name of the British people.
Among those who emerge sodden in moral sewage are Straw, Tony Blair, Jacqui Smith and David Miliband. The fact that the Americans were up to their neck in filth as well is scarcely an excuse.
Nothing which the anti-war movement alleged against the occupation of Iraq came close. Abu Ghraib wasn't the half, or the hundredth, of it. Afghanistan was worse again.
The treatment by British interrogators of the 'hooded men' at Ballykelly base (not Palace Barracks, as has previously been assumed) and of IRA suspects at Castlereagh holding centre was just more of the same.
Those who carried out the torture in the north will have felt entitled by past experience to assume there would be no comeback from British politicians.
As Cobain meticulously demonstrates, they were right - notwithstanding a raft of inquiries, assurances and apologies. (Never believe a British inquiry into wrong-doing by British forces, would be a useful lesson for now.)
We tend to assume that torture is something practiced by swarthy countries without the civilised traditions of the West. Praise for the moral standing of British forces is the stock-in-trade of Westminster politicians. This notion won't survive a reading of this book.
Cobain concludes: "Far from being alien, torture can be seen to be as British as suet pudding and red pillar boxes."