US prosecutors have claimed a Libyan man freely confessed to taking part in attacks on Americans, including the 1988 Lockerbie bombing and an aborted attempt to assassinate a US politician with a booby-trapped overcoat.

Abu Agila Mas'ud Kheir al-Marimi is said to have admitted his role in the murder of 270 people when Pan Am 103 was brought down over the Scottish town, when he was questioned in a Libyan detention facility in 2012.

Known as Mas'ud, the 74-year-old has claimed that three masked men forced him to make the statement after threatening him and his family.

His lawyers are trying to stop it from being used as evidence in his trial in Washington next year.

In response, lawyers from the US Department of Justice have said they can prove in court that the statement was voluntary, reliable and accurate.\

The existence of Mas'ud's alleged confession was first revealed in 2020, when the US announced it was charging him with building and priming the bomb used on Pan Am 103.

The father-of-six is accused of being a former colonel in Libya's intelligence service and has been in US custody since 2022.

Mas'ud has pleaded not guilty to the charges and is due to stand trial at the District Court for the District of Columbia in April.

Mas'ud's lawyers are trying to stop the jury from hearing about the statement and have filed a motion asking for it to be suppressed.

They contend it was obtained under duress following the revolution which toppled Colonel Gaddafi in 2011.

According to the police officer who questioned Mas'ud, the facility was well run, the prisoners were not restrained and there were no signs of torture or coercion.

The FBI has also claimed he had admitted building a device which exploded in a West Berlin nightclub in 1986, killing three people, including two US servicemen, and injuring dozens more.

It was January 2017 before the Libyan authorities provided a copy of the alleged confession to Scottish investigators, who gave it to the Americans.

A hearing to decide whether the statement should be withheld from the jury will take place in due course.