An investigation is to be launched into Tokyo's 2020 Olympics bid activities, the Japanese Olympic Committee (JOC) has announced.

The JOC said on Wednesday that a panel – including outside lawyers and an accountant – had been set up to look into the consultancy agreement between the Tokyo 2020 Bid Committee and the Singaporean company Black Tidings.

A newspaper report alleged the bid team paid around €1.3millon (£1m) to a Black Tidings bank account during the successful push to seal the right to host the the Olympic Games.

The account was in the name of Ian Tan Tong Han, a consultant to Athlete Management and Services – a subsidiary of Dentsu Sport set up to market and deliver commercial rights granted by the IAAF.

Han is reported to have links with Papa Massata Diack – the son of disgraced former IAAF president Lamine Diack, who resigned as an honorary member of the International Olympic Committee and president of the International Athletics Foundation in November last year amid accusations he took bribes to defer doping sanctions against Russian drugs cheats.

The younger Diack is a former consultant for the IAAF who was hit with a lifetime ban from athletics in January following disciplinary hearings over his alleged involvement in a doping cover-up relating to Russian London Marathon winner Liliya Shobukhova.

The investigation panel is headed by Yoshihisa Hayakawa, professor of law at Rikkyo University, and he is joined by fellow lawyer Kazuki Shishido and accountant Keiichi Kubo.

It was revealed the first meeting will take place on Thursday.