Japanese agency Kyodo News reported that plans for the Torch Relay to be held behind closed doors are being considered if emergency measures are still in force when the domestic Relay is scheduled to begin on March 25.

Tokyo itself has been under a state of emergency since January 7 and other regions of Japan have followed suit.

Although Tokyo 2020 insist that the 121-day Relay involving some 10,000 runners will remain as originally planned "in principle", they confirmed last month that some details could change.

"COVID-19 countermeasures will be worked on continuously for the Torch Relay," said organisers.

"For the Torchbearers, the officials working on the programme and the citizens in the local municipalities, we want to make sure that everyone's health is secure."

The Relay typically attracts large crowds and it is thought that runners could be restricted to areas such as parks and sports arenas where the number of spectators may more easily be controlled. 

The arrival of the Flame at each staging post is normally accompanied by a celebration event but this might also be scaled down or even held behind closed doors.

The Flame itself has been kept alight ever since it was kindled from the rays of the sun in March 2020 at the site of the ancient Games in Olympia.

No spectators had been allowed into the archaeological site during the ceremony. 

This was held before a small gathering which included Tokyo 2020 officials, International Olympic Committee President Thomas Bach and Coordination Commission chairman John Coates.

The Relay was suspended on its first full day in Greece after crowds flocked to see film star Gerard Butler carry the flame in Sparta.

The formal handover in Athens was also conducted without spectators.

Tokyo 2020 was represented by 1996 Olympian swimmer Naoko Imoto, resident in Greece where she works as head of education for the United Nations children's agency UNICEF.

Imoto was called up at the last minute after plans to send triple Olympic champion judoka Tadahiro Nomura and three time wrestling gold medallist Saori Yoshida were cancelled shortly before the official Tokyo 2020 Go flight set off for Athens.

In the week before the postponement of the Games to 2021 was announced, a lantern with the Flame was put on display at Sendai railway station in Miyagi prefecture. Local sources estimated that 50,000 gathered to see it.

Since then organisers have held a touring exhibition with a lantern containing the Flame, but a similar display of Olympic and Paralympic Torches has been cancelled because of the state of emergency.

Alterations to the Torch Relay route are by no means unprecedented. In 1948, the Relay route in Greece was shortened to avoid fighting in a Civil War.

In 2008 demonstrations against Chinese Government policy forced organisers of Beijing’s International Relay to make last minute revisions in London, Paris, San Francisco and Canberra, while in the Pakistani capital Islamabad, runners carried the Flame in the Jinnah Stadium rather than the surrounding streets because of security concerns.

The journey of the previous Tokyo Flame in 1964 was also interrupted and diverted. This was after a typhoon in Hong Kong caused damage to the aeroplane transporting the Flame.