Nine young men will be sentenced for their part in a £900,000 fraud on the elderly linked with the so-called "Bank of Terror" in Syria.
The fraudsters targeted elderly people aged between 72 and 94 from Dorset, Cornwall, Kent, London, Bedfordshire and Hertfordshire.
Former X Factor contestant Nathan Fagan-Gayle, 29, from London, was convicted of laundering £20,000 from 73-year-old Elizabeth Curtis who was duped into handing it over by a fake police officer in May 2014.
Breaking down in tears during a taped interview, Miss Curtis said: "I was absolutely stunned and shocked and could not believe I had been so stupid and naive as to be taken in."
In all, Miss Curtis was persuaded to transfer around £130,000 to different accounts.
The court heard singer-songwriter Fagan-Gayle, from Tower Hamlets, east London, went on a shopping spree and used some of the cash to hire a car in the United States.
In a separate trial last year, Mohamed Dahir, 23, Shakaria Aden, 22, and Yasser Abukar, 24, all from north London, were found guilty of conspiracy to commit fraud between May 2014 and May 2015.
Following the convictions, it emerged that Jeremy Corbyn, in his role as Islington North MP, had sent a letter in support of Dahir's original successful bail application last May.
Other defendants had pleaded guilty to their part in the fraud - either as conspirators or money launderers - and are also due to be sentenced by Judge Anuja Dhir QC.
They are: Fahim Islam, 21 of east London; Ahmed Ahmed, 23 of north London; and Makhzhumi Abukar, 23 from north London; Anrul Islam, 24, from Dagenham; and Warsame Sheik, 30, from Harrow.
The juries were not told that the con was uncovered by the Met's Counter Terrorism Command (SO15) after a separate terror probe found suspicious payments into a bank account of someone who is now in Syria.
Speaking after the earlier convictions in December last year, Commander Richard Walton, head of the Met's Counter Terrorism Command (SO15) said: "This was a scam on a huge national scale detected by specialist financial investigators who have stopped the targeting of even more victims.
"We uncovered this fraud after a separate terrorist investigation found suspicious payments into a bank account of an individual who is now believed to have travelled to Syria."