TOKYO (AFP, REUTERS) - Tokyo Olympics organisers reported the first infection from the nationwide torch relay on Thursday (April 22), as the pandemic continues to play havoc with the massive event.

A police officer helping with Japan's Olympic Torch relay the first participant in the event to be diagnosed with Covid-19, they said.

A man in his 30s tested positive for the virus after working on the relay in Kagawa prefecture on Japan's southern island of Shikoku, Tokyo 2020 said in a statement.

The officer was guiding traffic in the town of Naoshima on Saturday and came down with a fever on Sunday, the Asahi Newspaper reported, citing organisers and prefectural police. The man wore a mask and had no contact with runners, the report said.

Separately, two runners, a TV personality and a former Olympian, dropped out of a relay event due to be held in the western prefecture of Tottori next month, public broadcaster NHK reported.

Public support for the Games has waned amid concern the event will exacerbate COVID-19 infections, now battering the country in a fourth wave. Japan's government is expected to declare a state of emergency, the third in the past year, in the major population centres of Tokyo and Osaka this week.

The Games, already delayed by one year, are due to start in 92 days. Olympic and government officials have said further postponement of the Games is out of the question.

The organisers pledged to work with the medical authorities to "take the precautions needed to put on a safe and secure torch relay".

It was the first reported case related to the relay, which has been forced off public roads in some areas over fears it will spread the virus.

The historic city of Kyoto is the latest to express doubts, with local media reporting that the city's government will ask to hold the event away from public roads.

The Asahi daily reported that Kyoto may suggest holding the relay inside the city's Nijo Castle - a Unesco world heritage site.

The torch was carried around a closed course at a park in nearby Osaka last week, with the general public kept away.

Okinawa in southern Japan and Matsuyama city in the west of the country have also scrapped the public torch relay over rising Covid-19 cases.

Organisers insist the relay, which involves around 10,000 runners passing through all 47 prefectures, can be held safely under strict antivirus guidelines.

They have warned that parts of the relay could be suspended if too many spectators gather in one place.

The relay got under way on March 25, with spectators barred from the departure ceremony and first leg.