Outlining the case, prosecutor Richard Southern QC said on the day of the theft Maher had been on the delivery run with colleague Peter Bunn, who was responsible for carrying cash from the van to the bank.
He said: "Mr Bunn recalls that when they arrived in Felixstowe the bank was not open and he had to wait a while.
"Once inside he was delayed and tried to contact Mr Maher to tell him. He could not make contact but was not at that point concerned because the radio signal was variable.
"It was not until he came out of the bank that he found the van had disappeared."
It is thought Maher drove the van to nearby Landguard Point where he got into its secure area and loaded about 30 sacks of cash into a stolen getaway vehicle.