A UK hacker has pleaded guilty to stealing $12m (£8.7m) of gaming chips from online gaming firm Zynga.

Ashley Mitchell, from Paignton in Devon, admitted to hacking Zynga’s system and stealing 400 billion chips. He then sold around £50,000 worth of chips before being caught. At Exeter Crown Court he admitted five counts relating to the hacking.

"The defendant sold around one third of the 400 billion poker chips and looking at the auction history where one can purchase such items he was selling them for around £430 per billion," said Prosecutor Gareth Evans. "By my reckoning the total value if sold on the black market of the 400 billion was in the region of £184,000."

Had Zynga sold the chips itself the value would have been around $12m, ThisIsSouthDevon reported.

Mitchell had previously been given a suspended sentence in 2008 for hacking in to his local council’s database and changing his personal details.

US firm Zynga is the maker of the hugely popular Facebook games Farmville and MafiaWars.