The International Olympic Committee is investigating a media report that National Olympic Committees and Authorised Ticket Resellers broke rules over the sale of London 2012 tickets.
The IOC is also referring the allegations to its independent Ethics Commission.
The early edition of the UK's Sunday Times newspaper said several National Olympic Committees and Authorised Ticket Resellers were willing to break the rules by offering to buy or sell tickets outside their territories, to sell tickets at inflated prices or sell tickets to unauthorised resellers.
The London Olympics start on July 27th.
