Warren was convicted in 2009 after being accused of a plot to smuggle £1 million worth of cannabis into the Island. The 49-year-old is still fighting to clear his name.
Shortly before he was sentenced it was revealed that prosecution costs had led to the States paying just over £1 million.
But in the States this week, Attorney General Tim Le Cocq said that since July 2007 the amount of money spent on prosecuting the group was £1,963,619.