The two companies have been attributed to the “Passenger Rail Transportation Services” category within the second-tier sponsorship scheme for the Olympics and Paralympics in four years’ time.

The announcement brings the total number of domestic partners for the Games to 36, 21 of which are Official Partners.

“On this occasion, I am delighted to welcome Tokyo Metro and JR East as Tokyo 2020 Official Partners,” Tokyo 2020 President Yoshirō Mori said.

"Japan’s rail companies are known throughout the world for their extremely efficient operations.

“JR East operates an extensive rail network that covers the entire Kanto region and stretches as far north as the 2011 disaster-affected areas, while Tokyo Metro provides invaluable support to Tokyo’s world-renowned subway system.

“In partnership with these two companies, I am confident that we will be able to realise safe, punctual and comfortable rail transportation services for all visitors to the Tokyo 2020 Games.”

Tokyo Metro, a privately held company formed in joint partnership by the Tokyo Metropolitan Government and the Ministry of Land, Infrastructure, Transport and Tourism is a subway operator in the Japanese capital which began operating in 1927.

They helped with the completion of the Hibiya Line in the city in time for the last edition of the Olympics to be staged in Tokyo in 1964.

The railway network operated by JR East, which will celebrate its 30th anniversary next year having been established in 1987, consists of around 1,660 stations and spans 7,400 kilometres.

JR East already has involvement in sport as the company have a 50 per cent stake in the JEF United Ichihara Chiba football team, which plays in the J-League Division Two.

“We are honoured to have the opportunity to contribute to the success of this event,” JR East President and chief executive Tetsuro Tomita said.

“Acting in its capacity as a company operating in the East Japan area, JR East will help ensure that the Tokyo 2020 Games proceed without issue while contributing to the growing enthusiasm surrounding this event by providing safe and comfortable transportation services and revitalising local industries.

“Moreover, through these efforts, we will endeavour to create an important legacy that will continue to benefit communities long after 2020.”

The deals with the two transport companies are the first to be announced since allegations surfaced concerning a suspicious payment totalling $2 million (£1.3 million/€1.7 million) made by Tokyo 2020 to Black Tidings, a Singapore-based firm with links to the son of former International Olympic Committee member Lamine Diack, during its successful campaign. 

Black Tidings is already under investigation by French prosecutors as part of an inquiry into its use to channel money involved in the cover-up of Russian doping cases.

Japanese Olympic Committee President and Tokyo bid leader Tsunekazu Takeda insists the fee was for legitimate consultancy work, but the French probe is continuing.

Takeda has been unable to satisfactorily explain what the money was for, while Mori has insisted he bears no responsibility for the problems currently being faced by Tokyo 2020, claiming he would have "had to be God to have predicted them".