MELBOURNE (REUTERS) - Former Australia chef de mission and Olympic rowing champion Nick Green has cast doubt on the Tokyo Games, saying it would be "very difficult" to hold the event in July as the world grapples with the global coronavirus pandemic.

Green, who led Australia's delegation to the 2012 London Olympics, said the widespread bans on mass gatherings by governments over the past two weeks had changed his mind about the chances of Tokyo going ahead.

"A couple of weeks ago, I was as confident as everyone else, saying the Olympics would go ahead, no problem," Green told Fairfax media.

"Only the world wars have stopped the Olympics from proceeding aside from a few boycotts here and there.

"I'm pretty robust about it but I don't have the same robustness in my thinking now. I actually can't see how the Games can go ahead, to be frank."

Green, 52, was a member of Australia's celebrated "Oarsome Foursome" that won back-to-back golds in the coxless four at Barcelona in 1992 and Atlanta four years later.

"My initial instinct was, this will be managed and it will be business as usual pretty quickly," he said of the virus, which has now infected over 212,000 people and caused 8,700 deaths in 164 nations.

"But now the information that's being presented ... makes it clear it would be very, very difficult for an event like the Olympics to occur considering every other single event globally on mass gatherings of people have been either cancelled or suspended indefinitely."

Global sport has been brought to a virtual standstill by the virus, with major tournaments including golf's Masters, the French Open tennis and soccer's European Championship postponed in recent days.

Green said the very nature of an Olympics, which herds thousands of athletes into a high-security athletes' village for their accommodation and meals, would be a health risk.

"The way the Olympics has operated in the past is .... 10,500 athletes descend on the Olympic village and they usually go from bubble to bubble from a security point of view," he said."But in today's environment, that's probably the worst thing ... having 10,500 athletes in one location at the one time."