Kyodo News reports that measures could be implemented to try and reduce roadside crowds in order to prevent the spread of coronavirus.

It is expected that those with sporting and Olympic connections will still participate.

The majority of Torchbearers had been assigned their slot before the postponement of the Games was announced in March and organisers undertook to ensure that wherever possible that they would be allowed to run in 2021.

An unnamed local official told the news agency "it is unthinkable to rearrange the relay participants". 

"Besides I don't know where to draw the line on who is a celebrity," they added.

There may be restrictions on the caravan of vehicles which normally precedes the Torch runner. 

In previous years, sponsor representatives have run alongside the trucks distributing flags, stickers and other souvenirs to spectators on the roadside.

Back in March, the presence of Hollywood film star Gerard Butler as a Torchbearer in Sparta forced organisers to curtail the relay after "unexpectedly large crowds" turned out. 

Butler had starred as the heroic Spartan King Leonidas in the film 300 and had been invited by the municipality as part of commemoration events for the 2,500th anniversary of the Battle of Thermopylae.

The handover ceremony in Athens last March was much reduced and attended by only a small number of officials.

When the Flame arrived in Japan, there were large crowds when it was displayed in a safety lamp at Sendai railway station in Miyagi prefecture, an area badly affected by the earthquake and tsunami in 2011.

Non-sporting celebrities have been a regular part of the torch relay since 1988 when Jang Yoon-jeong, then Miss Korea, carried the Flame en route to the Seoul Games.

In 2000, singer Olivia Newton-John carried the Flame in the shadow of the Sydney Harbour Bridge on the eve of the Games.

The late Christopher Reeve, star of the Superman movies, was among Torchbearers for Salt Lake City 2002. 

Angelina Jolie was to have carried the flame for Athens 2004 but was forced to pull out after a conflict in shooting schedules.

Movie star Jackie Chan lit the a cauldron in Sanya City early in its journey to Beijing in 2008 and renowned film director Zhang Yimou was among other bearers.

At London 2012, veteran entertainer Sir Bruce Forsyth exchanged the Flame at the very spot where the Olympic marathon had finished in 1908, but organisers came in for widespread criticism when reality television singing duo Jedward and American rapper will.i.am were also allowed to run.

During the most recent Torch Relay for the 2018 Pyeongchang Winter Games, a number of runners were drawn from K-Pop bands. 

These included Takuya, the Japanese singer in boyband Cross Gene.

Tokyo 2020 organisers are expected to announce further details about their Torch Relay this week. 

Meanwhile the Flame, which has been kept alight since March, is continuing a tour of 14 prefectures displayed in a safety lamp.