Two weeks of 'good cop, bad cop' interrogation awaits suspects

The men will be held separately in small cells where for the first two days they will be denied contact with their lawyers and families. Police interrogation techniques are designed to take advantage of the men's vulnerability, which is perceived to be at its greatest at this time.

Louise Christian, the solicitor who represented two of the former Guantanamo Bay detainees held at Paddington Green for a short time before their release, said that the specialist interrogators still rely on the "good cop, bad cop" routine.

Using this tried and tested formula, the detectives try to undermine the suspect's confidence as one officer acts as a sympathetic friend while the other threatens and cajoles.

Ms Christian said: "One starts off being nice and reasonable and tries to get them to chat. Then the other comes in later and by being quite rude and offensive tries to provoke and shock the suspect into speaking."

The high-security detention cells are housed in the basement of police station, a long way from the reception area at the front of the Victorian-era police station. Prisoners are taken to a courtyard, through a series of locked doors, to the downstairs detention centre, which also houses the interview rooms used by both police officers and the suspects' lawyers.

Here conditions are very basic. There are no windows in the basement and suspects often complain about being cold in the winter and extreme heat in the summer.

But rules of the detention of terror suspects make it clear that they must be given adequate refreshments and allowed to have eight hours of sleep in every 24. Following complaints by lawyers, Muslim detainees are now also allowed access to prayer rooms.

Peter Carter QC, chairman of the Bar's human rights committee, says that officers must be careful not overstep the mark. Any interrogation involving torture or oppression is unlawful under human rights legislation and could render evidence obtained inadmissible.

Under the Terrorism Act 2000, the Metropolitan Police can hold a suspect for up to 48 hours without a judicial warrant. Further extensions have to be granted by a magistrate.

After 14 days, the Metropolitan Police Commissioner, Sir Ian Blair, will consider any evidence, including information obtained during police interviews, that might support charges against the men. He must then decide to either order the men's release or send a police file to the Crown Prosecution Service, where senior lawyers will advise on the prospect of a successful conviction in the public interest.