Some of the detainees have later re-surfaced at the US military detention centre at Guantánamo Bay, Cuba, but the whereabouts of countless others remain unknown.

Amnesty International is calling on President Musharraf to end arbitrary detention and ‘disappearance’, and to publish a list of all places of detention and a register of all detainees.

Amnesty International’s 106-page report shows that a large number of ‘war on terror’ detainees have been literally sold into US hands by ‘bounty hunters’ who have received cash payments in return, typically $5,000. These arbitrary detentions (not ones involving other cases where international arrest warrants and rewards exist), have bypassed normal law enforcement procedures. It is believed, for example, that the majority of Guantánamo prisoners were sold into US custody.

Cash inducements do not in themselves contravene international law, but Amnesty International is extremely concerned at a pattern of arrests based on little more than the allegations of those who stand directly to benefit from them. Meanwhile, in some cases children as young as 10 have been illegally apprehended, including being sent to face indefinite detention at Guantánamo Bay.

Amnesty International’s report also gives details of torture endured by many detainees, including a 14-year-old boy from Chad hung up by his wrists in a prison in Karachi and regularly beaten with a metal rod over a 20-day period. He was later sold to US forces and taken to Guantánamo, where he remains.

West Midlands Amnesty International Media Officer, Simon Ware said:

“Whereas ‘disappearances’ were virtually unheard of in Pakistan before 2001, since the start of the ‘war on terror’ hundreds of people have been subject to illegal detention after arbitrary arrests by secret intelligence forces.

“In many cases there is evidence of the direct involvement of US operatives (CIA and FBI) in Pakistan’s wave of ‘disappearances’ and other human rights abuses, including rendition and torture.

“Despite secrecy and official denials, it is clear that the road to Guantánamo starts in Pakistan. President Musharraf must come clean about Pakistan’s ‘disappearances’.”

Most of the known victims of the USA’s secret ‘renditions’ programme were initially detained in Pakistan, and two-thirds of the Guantánamo prisoners whose origins are known were originally taken from Pakistan (approximately 500 people). Many detainees have been illegally transferred to US detention centres like Bagram Airbase in Afghanistan or to secret US-run 'black site’ prisons in unknown locations.

One typical example is that of Moazzam Begg, a British national and Birmingham resident. He was abducted at gunpoint late at night from his home in Islamabad in January 2002 by Pakistani officials (presumed to be secret intelligence forces) and US nationals (also thought to be secret intelligence agents), including “a very badly disguised” American “dressed to look like a Pakistani”.

Mr Begg was hooded, handcuffed and thrown into the boot of a vehicle, before being detained at a facility apparently run by Pakistan’s intelligence service, the ISI. He was denied access to a lawyer, his family or the UK consulate, and was repeatedly told he had been detained at the behest of the US, with one Pakistani official informing him that “if we don’t, we’ll be hit hard by the Americans’, by President Bush’s army”.

Begg was questioned in secret detention at a private residence by US interrogators in the presence of UK intelligence officials who refused him consular help or any other assistance. He was later taken out of the country to Afghanistan - where he was allegedly tortured - before being further transported to Guantánamo Bay, where he was held for more than two years before being released without charge in 2005.

Moazzam Begg said:

“My family began ‘habeas’ proceedings in Pakistan on my behalf after I was abducted. A judge even issued an order to the Ministry of the Interior instructing me to be released or brought to court. It replied with a sworn statement that I was not in their custody. Of course I wasn't: they'd already handed me over to the Americans.”

Amnesty International’s report records how Pakistan’s already poor human rights record has declined still further during the ‘war on terror’, with ‘disappearances’ now spreading beyond terror suspect cases to also affect Baloch and Sindhi nationalists, as well as journalists attempting to cover sensitive topics like Pakistan’s reaction to violent disturbance in the country’s tribal areas.