Major advertising agency ADK Holdings has reported that it participated in bid rigging for the rights to organize test events for the Tokyo Olympics, a source close to the matter said Tuesday.

ADK came forward after Tokyo prosecutors recently launched an investigation into bid-rigging allegations in connection with the test events, in addition to a scandal involving a former games organizing committee executive allegedly receiving nearly ¥200 million in bribes from five companies, including ADK.

By reporting the alleged violation of the antitrust law and offering to cooperate with the Japan Fair Trade Commission, ADK is hoping for leniency, such as the avoidance of criminal charges and a reduction in fines.