The Mayor of London, Sadiq Khan, has ordered an investigation amid concerns over the increasing finances of West Ham United's London Stadium.
In 2015, former mayor Boris Johnson said the change from an Olympics arena to a football stadium would cost £272m, a figure which has now risen to £323m.
The investigation will look into inherited issues including the cost of moving the retractable seating.
A stadium expert has said the ground should be knocked down and rebuilt.
Paul Fletcher, who has built or advised on more than 30 new grounds, said it should be rebuilt as fans are too far from the pitch so it is not suitable for football.