The evidence springs from two cases in which 'confession' evidence has been challenged by Palestinian suspects who claim they were tortured by Shin Bet. During court hearings the authorities have openly or tacitly admitted practices that have for years been alleged by defendants and documented by lawyers, but never discussed openly by Shin Bet.
In a case at Hebron military court, in the West Bank, Shin Bet officers have admitted that before the suspect, Mohammed Adawi, 'confessed' to membership of the Islamic military group Hamas, he was subjected to torture. Over three separate periods of four, three and five days he was hooded and deprived of sleep while chained in a contorted posture to a miniature chair and confined to a box-sized isolation cell.
Immediately before he confessed Mr Adawi had spent 39 hours in such a state. Mr Adawi, 26, also says he was subjected to constant loud music and beaten - allegations Shin Bet did not admit. However, Shin Bet has previously testified that 'extraordinary measures' can be used against some detainees. Middle East Watch, the human rights group, says there is sufficient evidence to suggest that these 'extraordinary measures' include severe beatings of the body, testicles and throat.
In a second current case, a defence lawyer, Tamar Peleg, gained access during a hearing in Tulkarm to a secret medical form. It asked that the doctor responsible for examining new detainees say whether the suspect, Ribhri Shukeir, would be able to stand four kinds of abuse. They were: prolonged isolation; tying up or handcuffing; hooding or blindfolding; and prolonged standing. The doctor answered 'yes' to all four.
Mr Shukeir, accused of membership of Fatah, a faction of the Palestine Liberation Organisation, was then held for 50 days in the interrogation wing of Tulkarm Prison, during which time he too was hooded, bound to a small chair, held in a tiny cell, and deprived of sleep. He said his interrogators also beat him on his back and stood on his hands.
Both cases have provided a rare insight into the workings of Shin Bet. Lawyers say the fact that the authorities are now prepared to give evidence about some of their practices strongly suggests they are condoned in the secret code.
Amnesty International and other human rights groups have long argued that Israel is condoning interrogation practices that constitute 'inhuman and degrading treatment' under the terms of the Geneva Conventions and, in some cases, 'torture'. Although death in custody is not uncommon in the occupied territories, Israel is not accused of routinely employing more extreme torture methods. Rather, the criticism is that Israel has institutionalised low-level torture and used it on a huge scale.
More than 35,000 Palestinians have been arrested since the intifada began in 1987. The majority have been convicted on 'confession' evidence alone. Many have made allegations of torture. The secret code was drawn up after the controversial Landau Commission report of 1987, which sprung in part from the case of two Palestinians who died under torture at the hands of Shin Bet. To thwart 'terrorists', the commission ruled that it would sometimes be 'necessary' to use 'non-violent psychological pressure . . . acts of deception . . . and a moderate measure of physical pressure'. A case pending before the High Court demands that a secret annexe detailing 'moderate physical pressure' be made public.