At a separate court case, PKF were accused of unlawfully obtaining telephone records of West Ham vice chairman Karren Brady during the bidding process.
West Ham initially beat Tottenham to take over the Olympic Stadium in 2011 but the deal collapsed amid legal challenges from London clubs Tottenham and Leyton Orient.
West Ham has since agreed on a new 99-year deal to move from its nearby Upton Park and rent the revamped 486 million pound ($781 million) venue starting in 2016.
The 80,000-seat stadium, which hosted the opening and closing ceremonies and the track and field competition at the 2012 London Games, will be downsized to 54,000 seats and reconfigured with a new roof and retractable seats.
As the anchor tenant, West Ham will have primary of use of the stadium, although the venue will retain the running track and stage other sporting events and concerts.