Inquiry Needed! Was Tony Blair complicit in the torture of Shaker Aamer in 2002?

Several UK national and international newspapers have reported allegations by the Guantanamo Bay prison survivor that the UK Prime Minister at the time - Tony Blair - personally accompanied UK secret service officials on a visit to Bagram airbase, Afghanistan, during which Aamer claims that these officials were present at his interrogation and torture. Shaker Aamer was afterwards held at Guantanamo Bay detention center until 2015, despite the USA authorities deciding in 2007 not to press charges against him.
If Tony Blair was aware that anyone was being, or was likely to be, tortured at Bagram during his visit, and failed to act against this, he committed Grave Breaches of the Third and Fourth Geneva Conventions. Such breaches constitute a War Crime in international law, and would legally render Blair a War Criminal, subject to obligatory arrest and trial wherever he goes.
In times of peace as well as war it is crucially important that issues related to torture should not be ignored or left ambiguous, however powerful or influential the alleged perpetrators may be. Peoples' perception of the behaviour of war-endorsing governments during this period is already tarnished around the world. The failure to properly address such issues promotes further conflict, and to ignore them, while the alleged perpetrators freely travel the globe, mocks the very values to which all nations and states claim to aspire.