The Manchester attacker's brother purchased bomb-making chemicals and helped make detonators before the terrorist atrocity, a court has been told.
He has been charged with the murder of the 22 people, who were killed as Ariana Grande fans poured out of a concert at Manchester Arena, and the attempted murder of the 260 injured victims.
Mr Abedi, now 22, was arrested in the Libyan capital Tripoli and extradited to the UK in July.
It is claimed he made both successful and unsuccessful attempts to buy bomb-making chemicals.
He also allegedly helped to purchase a Nissan Micra, which was used to store device components, and made detonator tubes for use in the bomb.
Mr Justice Baker did not ask Mr Abedi to enter pleas and the hearing was adjourned until later this month.
His defence lawyer told a previous hearing that he would be denying all charges.
Mr Abedi, who was remanded custody, is due to go on trial in November.
Additional reporting by Press Association