A police probe into former Suntory Holdings Chairman and CEO Takeshi Niinami’s alleged involvement in the import of supplements containing illegal drugs has highlighted how big the gray area might be in Japan.

What is currently at the center of police investigations is a supplement allegedly imported by another man that is said to contain tetrahydrocannabinol (THC), a cannabinoid derived from the cannabis plant that gives the “high” often associated with marijuana.

Cannabis contains two major substances — cannabidiol (CBD) and THC — as well as other rare cannabinoids.