TV Asahi reported the man in his 60s has been hospitalised owing to his age and pre-existing conditions.

He is the first foreign official to be hospitalised because of COVID-19 on arrival in Tokyo.

In its daily update, Tokyo 2020 confirmed there had been four more positive cases among people who touched down in the Olympic and Paralympic host country yesterday.

The three others are all contractors working on the Games, scheduled to open on July 23.

Tokyo today recorded 1,271 new COVID-19 cases, marking the 27th day in a row where the tally is higher than a week prior.

It is also the third straight day where the total number of infections has topped 1,000.

At least five athletes have tested positive for COVID-19 since arriving in the Japan for the Games, while the Refugee Olympic Team delayed its travel to Tokyo after one of its delegation also returned a positive test.

Teams from several other nations have been forced into isolation due to COVID-19 issues, raising concerns over the impact of the virus on athletes who are set to compete at the Games.

Australian Alex de Minaur today became the latest player to pull out of the tennis tournament at Tokyo 2020 after testing positive for COVID-19.

De Minaur, the world number 17, joins a list of absentees from the Olympic competition which also includes 20-time Grand Slam champions Roger Federer and Rafael Nadal, Austria's Dominic Thiem, Canada's Denis Shapovalov and Federer's compatriot Stanislas Wawrinka.

The 22-year-old tested positive twice in Australia and has not travelled here.

The IOC and organisers have faced criticism for pressing ahead with organising the event during the pandemic, but have insisted the measures that will be implemented will ensure the Games are "safe and secure".

The IOC has also cited its vaccination programme, where it has attempted to secure jabs for Olympic participants, as a reason for optimism.

It has claimed 85 per cent of residents in the Olympic Village have been vaccinated against COVID-19.

Large sections of the Japanese public have signalled their opposition to the Olympics and Paralympics going ahead, with calls for cancellation a common theme in the run-up to the Opening Ceremony.

Health experts have warned the Games could become a "super-spreader" event, while Shigeru Omi, the Japanese Government’s top COVID-19 advisor, has warned staging the Olympics during a pandemic is "abnormal".