Shoe bomber suspect Richard Reid was back behind bars in America last night after he was remanded in custody during a preliminary court appearance.

The 28-year-old Londoner was denied bail while the FBI continued to investigate allegations that he tried to blow up a plane from Paris to Miami using explosives hidden in his black suede basketball sneakers.

The court in Boston, Massachusetts, heard the "home-made bomb" would probably have created a sufficiently powerful blast to destroy the plane.

Reid, who was handcuffed and wearing an orange jumpsuit, was charged with intimidation or assault of a flight crew, which carries a maximum 20-year sentence, and the FBI has said further charges were likely.

FBI Special Agent Margaret Cronin told the court that Reid was carrying "a home-made bomb", and US government officials believe the plan may have failed because he was unable to light the fuse.

The detonator cord was non-metal and could have become too wet to light.

Tests on the explosive showed signs of PETN, a material used to make the explosive Semtex, the same explosive used by Libyan terrorists in 1988 to down Pan Am Flight 103 over Lockerbie, the government officials said.

FBI investigators were still investigating whether Reid was acting alone or with accomplices, and tracing his string of journeys across Europe and the Middle East earlier this year.

US officials were also checking claims from some Afghan prisoners that Reid trained with them at Osama bin Laden's terrorist camps in Afghanistan.

His lawyer, Tamar Birckhead, urged the public to keep an open mind about the Muslim convert, saying: "We are unaware of any evidence to support a link between the offence charged and any terrorist organisation or individual."

Earlier, it emerged that Reid told the FBI he had bought the material for the devices from a dealer he found on the Internet.

He said he had spent £1,000 on the PETN during a visit to Amsterdam.

Reid's parents were not available for comment about the decision, but have spoken of their shock.

His mother, Lesley Hughes, of Frome, Somerset, yesterday repeated her fears for her son and asked to be left alone to "come to terms with the current situation".

His father Robin Reid - who has not been seen at his south London home in for several days - told the Daily Mail his son must have been "brainwashed" into the alleged bomb attack.

"My son is a determined boy and I can imagine him being determined enough to blow himself to bits," he said.

But he could not believe his son would want to hurt anyone else and said he was not "a bad lad".

Mr Reid senior, described by his neighbours as a quiet man who seldom had visitors, said he only found out about his son's involvement when he saw his picture printed in newspapers on Christmas Eve.

The older man worshipped at the same mosque in Brixton, south London, that his son later attended, which is now at the centre of a row about whether police ignored warnings that radical Muslims were recruiting young men in London.

Details continued to emerge about Reid's possible connection to the so-called "20th hijacker", Zacarias Moussaoui, the only person charged with direct involvement in the September 11 terrorist attacks on the US. He attended the same mosque in London, but it was not known if he ever met Reid.

And Abdul Rahman Qureshi, a religious leader on the staff at Feltham Young Offenders' Institution in west London, where Reid was an inmate, was one of three staff members suspended since September 11 for making "inappropriate comments".

Mr Qureshi - suspended a few weeks ago and the subject of an investigation - was not believed to have been at Feltham when Reid was an inmate, in 1992 and again in 1994