A Ministry of Defence clerk is facing jail time for fraud and money laundering after stealing nearly £1m by entering fake expenses claims into the department’s online administrative system.

Southwark crown court heard on Monday that the former corporal Aaron Stelmach-Purdie, 34, had run the scam for just over a year between November 2014 and January 2016 while he worked in central London as a clerk at the MoD’s administrative headquarters.

Stelmach-Purdie, from Oldham in Greater Manchester, manipulated the department’s online platform for the management of staff expenses and allowance claims. He defrauded the government out of £911,677, keeping £557,093 for himself, the court was told.

The defendant, who was dismissed from the armed forces in January 2016 after he was convicted and sentenced on four counts of sexual activity with a child, used his joint personal administration (JPA) account, a system the UK armed forces used to pay staff salaries and process expenses, to make fraudulent claims.

Five other military clerks who were also employed at the Regent’s Park barracks – Roger Clerice, 28; Allan O’Neil, 48; Lee Richards, 41; Anthony Sharwood, 38; and Peter Wilson, 55 – appeared in court alongside Stelmach-Purdie after they were convicted over charges of money laundering and conspiracy to commit fraud.

The prosecutor, Dominic Connolly, told the court: “These defendants, who were all employed at the Regent’s Park barracks, made a series of fictitious claims to expenses and allowances that they were not entitled to. As a result of these frauds, there has been a loss of public funds totalling £911,677.66.

“These are public funds that had been demarcated for the defence of the realm and the protection of its armed services.”

Stelmach-Purdie was responsible for the management of claims for expenses and allowances, and used his JPA account and the accounts of others. He then used the bank accounts of third parties, including his mother and sister, to conceal the proceeds of the fraud, the court heard.

According to prosecutors, he approached the other defendants in December 2014 or shortly after, when he claimed he had found a way to “make some money manipulating JPA”. There were 161 fraudulent claims altogether, the court was told.

Clerice, who was Stelmach-Purdie’s line manager, worked as a sergeant in the department and was described as a “specialist in administration”. He received £7,691 from the fraud and later pleaded guilty to money laundering.

Richards, a former lance sergeant from Amesbury in Wiltshire, was convicted by a jury of 103 fraudulent claims made between March 2015 and January 2016, totalling £434,825. He retained about £160,000 of that sum, the court heard.

When police interviewed him, Stelmach-Purdie said he had become involved because of the state of poor mental health brought about by the sexual allegations made against him. He pleaded guilty to seven counts of conspiracy to commit fraud and one count of money laundering in August 2023.

All six defendants are scheduled to be sentenced at Southwark crown court on Tuesday.

Additional reporting: PA Media