In what you might call a joint statement, Tokyo 2020 organizers Tuesday noted the need to warn countries with relaxed cannabis laws that weed isn't allowed in Japan.

"There are countries and regions around the world that have relaxed rules recently on the use of cannabis," noted Tokyo 2020 CEO Toshiro Muto.

"The use of cannabis constitutes a violation of the law in Japan and that needs to be fully communicated," he added.

Cannabis rules in Japan are strict, with up to five years' prison for personal use and seven years for dealing. 

The issue hit the headlines in Japan when two Japanese snowboarders were punished after traces of marijuana were detected in their hair following a party in December 2015.

AFP