According to Avary, Microsoft consulted him in 2002 and 2003 for his creative thoughts on games that would appeal to women, and when he came up with the idea of the virtual yoga studio, which could then evolve into a customisable home fitness game, the software giant appeared to be very excited by the idea.
According to the suit, e-mails and "Scope of Work" documents were exchanged between the parties for a while, but communications dried up for about six months until, in September 2003, Avary was shown a Non-Disclosure Agreement that Microsoft wanted him to sign.
This, says the lawsuit, "would have resulted in Avary transferring all rights to his concept to Microsoft with no compensation to Avary." He did not sign.
Last month, Avary discovered that a new Xbox game called "Yourself!Fitness" was due to be published. Developed by Oregon-based responDESIGN Inc., the game shows a virtual yoga trainer who takes viewers through a yoga session and is, according to the suit, "in many respects identical to Avary's secrets and concepts".
Avary filed suit in a Los Angeles federal court on Monday, claiming that the game "incorporates concepts, materials and ideas owned and developed by Avary, and imparted to Microsoft in confidence".
The suit claims a breach of implied contract, fraud, unfair competition, breach of confidence, misappropriation of trade secrets and unjust enrichment. It seeks an injunction against further sales of the game, and damages of at least £30 million.
Microsoft has made no comment on the suit as yet, but in a statement responDESIGN CEO Ted Spooner called the allegations "completely false."
"Microsoft did not participate in the development of this product in any way, shape or form. This product was an original creation of responDESIGN and my partner Phin Barnes," he said.
The Yourself!Fitness idea was conceived prior to the dates Avary claims he shared his idea with outside parties, said responDESIGN.