An East Sussex building society worker who stole more than £20,000 from customer accounts has been told he will go to jail.

Robert John George, of Alder Close, Heathfield, took £21,150 by forging withdrawal slips from accounts at the Portman Building Society in Devonshire Road, Bexhill.

The 24-year-old, who pleaded guilty to nine charges of theft, was told by Judge Cedric Joseph at Hove Crown Court yesterday that he faced prison.

Eloise Marshall, prosecuting, told the court that George started work at the building society in December 2001.

She said: "He begun regularly stealing money from customers' accounts where he had some control, taking figures between £250 and £1,000.

"He continued until April 2002, when a customer noticed money missing from her account.

"When his manager and the head office investigated the matter, it emerged he had taken money from five accounts."

Ms Marshall said George had been forging signatures on withdrawal slips.

She said: "He told his manager he picked the accounts because there was no activity and they were not checked.

"He said, 'To be honest, they're all easy'. He said he spent the money. He was not in any financial trouble."

In a police interview George said he begun taking money when he changed branches.

Ms Marshall said: "He said he didn't know why he did it. After a withdrawal of £200 he realised no one was checking the accounts.

"He said, 'I just lost it'. It seemed he gained some enjoyment from the fact everyone else was blind to what he was doing."

She said no money had been repaid.

Rebecca Upton, defending, told the court the initial withdrawal arose out of a genuine mistake as he had miscalculated the amount in the till and had £100 over.

She said he realised it was wrong to take and keep the money but it had spiralled out of control.

But Judge Joseph replied: "It was entirely in his control. He was just greedy."

Ms Upton said George, who now works for a timber merchant, had been badly affected by the death of his grandmother at the time.

She asked the court to take into account his guilty pleas, previous good character and co-operation with the police, suggesting a combination of a community punishment order and curfew order.

She said: "The only way Mr George can continue to repay the money is if he keeps his job."

Ms Upton told the court George had taken out a loan of £3,000 to start repaying the money. She said the cheque was with her solicitor but the prosecution had not given them an address to sent it to.

Adjourning sentencing until Monday, September 1, at Croydon Crown Court, to allow the cheque to clear, Judge Joseph said: "I don't want him to think he's buying his way out of prison. He must understand there must be a prison sentence."