Because of the complexity of concocting such an explosive, FBI technicians believe that Reid must have had an accomplice

Boston Globe

Meanwhile in the UK, The Times newspaper said Mr Reid could be linked to Osama Bin Laden's al-Qaeda network, after it traced him to a London mosque also attended by a man charged with the 11 September attacks.

The leader of the Brixton mosque, in south London, told the newspaper that Mr Reid was incapable of acting alone.

He is reported to have converted to Islam in prison, where he served time for a string of convictions such as street muggings.

Richard Reid, whose identity is still being questioned and investigated, is now in custody and has been ordered to appear in a Boston court on Friday.

He is alleged to have tried to detonate explosives packed in the heels of his shoes on an American Airlines flight from Paris to Miami on Saturday, before being overpowered by passengers and crew.

Mystery man

"Because of the complexity of concocting such an explosive, FBI technicians believe that Reid must have had an accomplice," the Boston Globe said, quoting an unnamed Massachusetts official.

An FBI spokesman in Washington said that establishing whether the suspect acted alone was one of the main focuses of the investigation.

Passengers' footwear is now being screened

There are also questions about the man's identity.

French police sources in Paris said that Mr Reid also identified himself as Tariq Raja, born in 1973 in Sri Lanka, and as Abdel Rahim, a name reflecting a conversion to Islam.

Sri Lankan foreign ministry officials said there was no evidence to suggest he was a citizen of that country.

The British Consul-General in Boston, George Ferguson, told AP news agency there was no reason to believe Mr Reid's UK passport was not legitimate.

"His passport says he was born in the UK, in England," he said.

According to the report in The Times, he was born in 1973 in Bromley, south-east London. His mother is English and his father Jamaican.

Shoe checks

The BBC's Tim Franks says Mr Reid will appear on Friday for a "probable cause" hearing - to establish if there are sufficient grounds to hold him.

The passengers travelled on to Miami after questioning

The court has appointed a lawyer for him.

If convicted as charged so far, he faces up to 20 years in prison and a $250,000 fine.

The FBI is expected to file more charges against him.

French authorities are trying to establish how the passenger managed to get on board, given the heightened security put in place after 11 September.

Security has been stepped up at both France's Charles de Gaulle airport - where the flight originated - and Boston's Logan airport, to which it was diverted after Mr Reid was overpowered.

Passengers are now required to take off their shoes and put them through X-ray machines.