Abdel Basset al-Megrahi, a Libyan national convicted of bombing an aeroplane flying over the Scottish town of Lockerbie in 1988, has been denied bail by a Scottish court.

The decision by the court on Friday came after al-Megrahi's lawyers asked for their client to be freed on bail pending the outcome of an appeal against his conviction.

Al Jazeera's Fergal Parkinson, reporting from Glasgow, said that al-Megrahi is very ill.

"He is said to have an advanced form of prostate cancer, and wanted to be with his family until the appeal is lodged," he said.

"But Scotland's highest court has said no. Al-Megrahi, till this day, has maintained his innocence, and claims he was not involved in the Lockerbie bombing."

Al-Megrahi was convicted of blowing up a Pan Am jumbo jet as it flew from London to New York on December 18, 1988, killing all 259 people on board.

Eleven residents of the town of Lockerbie were killed by falling wreckage.

Al-Megrahi, 56, a former Libyan intelligence agent, was convicted in 2001 after a trial held in the Netherlands under Scottish law and sentenced to life in prison.

An initial appeal was rejected in 2002.

However, a Scottish criminal review body decided last year that al-Megrahi was entitled to another appeal on the grounds that he might have been the victim of a miscarriage of justice.