A federal jury has found an Illinois couple guilty of defrauding Best Buy out of $41 million by over-billing the Richfield-based company for computer parts.

Russell Adam Cole, 50, and Abby Rae Cole, 53, of Deerfield, Ill., were found guilty Thursday of mail fraud, wire fraud, conspiracy, tax evasion and conspiracy to commit money laundering in connection with the scheme.

The IRS led the investigation into the case.

According to prosecutors, Best Buy created a repair service on products in the early 2000s and solicited vendors to submit bids on certain parts they wanted to supply for the repair service.

The Coles owned and operated a computer parts distribution company called the Chip Factory, Inc. For about four years ending in August 2007, Best Buy accounted for most of Chip Factory's sales.

But court records showed that the Coles made Chip Factory quote fraudulently low prices in Best Buy's auction system to obtain computer repair parts. After winning bids, the Coles billed Best Buy prices that were higher than the ones quoted in the bidding process.

Over time, prosecutors said the Coles billed Best Buy for more than $41 million than had been agreed to in the bidding process.

A former Best Buy employee, 39-year-old Robert Paul Bossany of Prior Lake, helped carry out the scheme. Bossany pleaded guilty in January 2009 to accepting bribes from Chip Factory and conspiring to defraud Best Buy while working as Best Buy's primary contact with Chip Factory.