Hashem Abedi's fingerprints were on packs of nails in a car allegedly used to store a bomb-making kit linked to the Manchester blast, a court has heard.
The 22-year-old is accused of helping his brother Salman plan the Arena attack in May 2017.
Jurors heard his prints were also found in a flat allegedly used to stockpile chemicals used to make the bomb.
He denies 22 murders, attempted murder and conspiring to cause explosions.
Hashem's fingerprints were identified at a flat in Somerton Court, Blackley, Manchester, allegedly used to stockpile chemicals used to make the bomb, the Old Bailey heard.
Jurors were told they were also found at a house in Lindum Street, Rusholme which was used as a delivery address for items bought online via Amazon.
On Wednesday, jurors heard Hashem's prints were also discovered on a tin can linked to the bomb which killed 22 people and injured hundreds of others, a court has heard.
The bomb-making kit was allegedly left in a parked Nissan Micra car when the brothers travelled to Libya.
Salman allegedly returned to the UK alone just days before the attack at the end of an Ariana Grande concert and assembled the deadly device packed with shrapnel at a rented flat in Granby Row.
Following the suicide attack police recovered the Nissan Micra and examined it.
Fingerprint expert Philip Balduini told the court that both brothers' prints were in the car, which allegedly contained traces of triacetone triperoxide (TATP).
Hashem's prints were also on items including a cardboard box, two plastic bottles inside a holdall and a large blue drum, he said.
Jurors were told inside the blue drum were seven packs of assorted nails which also had Hashem's prints.
The trial continues on Monday.