How MI5 homed in on kitchen-sink lab

Inquiries were launched into group of young Algerians after tip-off from foreign intelligence services

IT WAS early in December that MI5 became suspicious of a group of young Algerians living in London – an investigation that would lead to seven arrests and the discovery of a makeshift poison laboratory with possible links to al-Qa'ida.

It was early in December that MI5 became suspicious of a group of young Algerians living in London – an investigation that would lead to seven arrests and the discovery of a makeshift poison laboratory with possible links to al-Qa'ida.

As the police issued a series of warnings in the approach to Christmas about the growing likelihood of a terrorist attack in Britain the inquiry was one of several looking into possible plots by Islamic extremists. Among the suspects were two teenage asylum-seekers and at least seven other men and a woman. None of the suspects was known to the law enforcement authorities, although some had been living in Britain for three years. Information about several of the suspects is believed to have been provided by a foreign intelligence service.

Officers from the Metropolitan Police's anti-terrorist branch and Special Branch were drafted in to work with MI5. It was not until late December or early January that the police and the Security Service were able to trace and identify the homes of most of the suspects.

One of the premises was the top floor flat at 352 High Road, in the run-down north London district of Wood Green, a melting pot of different nationalities and a mixture of Victorian terraces and bedsits. The one-bedroom flat was the home of two teenagers, aged 16 or 17, who were housed by Islington Council after claiming asylum. One is an Algerian who is thought to have sought asylum more than two years ago, while the other has an Ethiopian passport, but is also thought to be from Algeria.

Only one suspect was at the flat when police made a series of co-ordinated raids on five homes in north and east London in the early hours of Sunday. Six Algerian men, the oldest in his early thirties, and a woman were arrested. A woman, who was also detained, was released without charge.

When the Scotland Yard officers entered the Wood Green flat they had been warned that they might find a "kitchen sink" laboratory and some form of toxic substance. At first all they found were a few containers and pieces of apparently harmless kitchen equipment. But they also discovered a strange-looking substance, later described by police as a small "residue". This was sent to the Porton Down chemical and biological defence establishment in Wiltshire, and on Tuesday morning it was confirmed to be a highly toxic compound made from castor oil beans. The poison, ricin, can be fatal in small doses and there is no antidote. It can kill if it is injected, used in a spray, ingested, or rubbed on the skin in a cream.

The discovery caused great alarm within the Government – Tony Blair was immediately informed – and the health service. It was the first hard evidence that a group with suspected links to the al-Qa'ida network had produced a potential chemical weapon in Britain.

The good news was that all the evidence suggests that only a very small quantity of the poison has been produced and it was not suitable for a mass attack. The police have not found any plot to attack a specific target.

After the confirmation that a dangerous substance had been discovered, the police and the Government's deputy chief medical officer put out a nationwide alert.

While the Metropolitan Police was holding a press conference at 4pm on Tuesday, anti-terrorist officers raided another home in north London and arrested a seventh suspect, a man aged 33. He was being questioned last night as officers continued to search his home.

Police are continuing their search for any ricin that may have been taken away, and for other members of the alleged gang. "It is a bit like piecing together a big jigsaw – finding out who has been with whom, spoken to whom and lived together," said a security source.

John Wadham, director of the civil rights group Liberty, said: "These people may be guilty, they may not be. I would like to see some degree of calm in relation to the media and in relation to these arrests.

"We do see a lot of 'successes' by the security services and the police in relation to the arrest of so-called terrorists and they tend to be featured widely, but the consequences are not featured as much."

Recent arrests of several men in London were widely linked to a supposed plot to release poison gas on the Tube, he said, but the suspects were later found to have no connection to such a plan.