A mobile phone containing a clue to the Manchester Arena bomb plot was seized by police in an airport stop two months before the atrocity, a court has heard.
Later, investigators made a link with the owner of the phone, the purchase of 10 litres of sulphuric acid, bomber Salman Abedi and his brother Hashem, the Old Bailey was told.
Hashem Abedi, 22, is on trial accused of helping his brother to assemble chemicals and materials to build TATP explosives which were detonated on 22 May 2017 just as concert goers were leaving an Ariana Grande concert, killing 22 people.
On the third day of the trial, prosecutor Duncan Penny QC told how Hashem Abedi had turned to friends and acquaintances for help to buy chemicals to make TATP explosives, while keeping the reason a secret.
On March 15 2017, an Amazon account, belonging to his friend Mohammed Younis Soliman, was used to order 10 litres of sulphuric acid, jurors heard.
Mr Penny said £140 in cash was later paid into Mr Soliman’s account.
On March 23, Mr Soliman’s phone was examined and digitally downloaded when he was stopped at Manchester Airport, jurors heard.
Mr Penny told jurors: “Later on, when these matters were being investigated, a link between Soliman, his purchase of 10 litres of sulphuric acid and the brothers Hashem Abedi and Salman Abedi was identified.
“It was clearly no coincidence that someone with links to the brothers was being used to purchase sulphuric acid in large quantities and on their behalf.
“The sulphuric acid cost £128.46 including delivery. You’ll remember that on March 15 £140 had been paid into Soliman’s account.”
The examination of Mr Soliman’s phone revealed the defendant’s numbers were stored as Hashem Alabedi and Hashem, the court heard.
Hashem Abedi, originally from Manchester, has denied 22 counts of murder, attempted murder and conspiring with his brother to cause explosions.