“The Japan 2019 Organising Committee reminds all spectators that ticketing terms and conditions clearly stipulate that any person who attempts to access the field of play without authorisation risks having their tickets revoked and will be handed over to local police.

“Entering the field of play without authorisation is an offence in Japan and is punishable by law.”

The young man, yet to be identified, ran onto the playing field wearing Wallabies paraphernalia and crept up beside Beale during the match. He was not completely clothed, prompting a strong reaction from the crowd, before running from the field.

Afterwards, Beale laughed off the incident and said: “He got me really good,” and that it was “a bit of a blur”.

“He caught me by surprise,” Beale said. “I heard the crowd cheering and I thought, 'what is going on? Are they cheering because of the ruck? The ball is just in the ruck.'

"Then all of a sudden I felt something come over my left shoulder and he came up and he spooked me. I don’t think he got caught, he went back into the stands.”

The man was also sporting a number of tattoos, which is Japan are associated with Yakuza - the Japanese mafia.

While the man is likely to be released, Japanese authorities are renowned for not looking favourably upon public indiscretions.

Former Wallabies legend George Smith was held in police custody for 18 days in early 2018 on suspicion of evading a $110 taxi fare before assaulting the 58-year-old driver on the outskirts of Tokyo.

Smith was later released and no charges were laid but he was forced to apologise to his two clubs at the time, the Queensland Reds and Suntory, for not telling them about the incident.

Police prosecutors in Japan are given up to 23 days to hold a suspect without charge.

Do you know more? Contact tom.decent@smh.com.au