Amid the Japanese authorities¡¯ investigation into a bribery scandal related to last year¡¯s Tokyo Olympics and Paralympics, further allegations of bid-rigging by the nation¡¯s leading advertising firms for Games test events have surfaced.

Over the past week or so, investigators from the Tokyo District Public Prosecutor¡¯s Office and the Fair Trade Commission have raided several firms including Dentsu, Hakuhodo and ADK Holdings ¡ª Japan¡¯s top three advertising companies ¡ª over the case.

The new development came after the arrests of a former executive of the Tokyo Organising Committee and some other prominent business figures over alleged bribery.