The boss of the Japanese drinks giant behind Jim Beam and Lucozade has been ousted following a police investigation into his purchase of possibly illegal “supplements”.

Suntory, whose brands also include Ribena and Roku gin, was told two weeks ago by its chief executive and chairman, Takeshi Niinami, that he was being investigated by Japanese police over the supplements which he claimed he bought “on the understanding that they were legal”.

The company did not disclose what type of supplement Niinami, 66, is alleged to have bought, but did confirm that they were not part of Suntory’s own health and wellness range.

Bottles of Yamazaki whisky on a shelf.

Suntory brands include a portfolio of Japanese whiskies

AKIO KON/BLOOMBERG/GETTY IMAGES

Nippon TV claimed that the businessman was suspected of importing supplements containing THC, the active ingredient found in cannabis, from the United States. He reportedly told local police that he thought it was a legal product and that a “female acquaintance sent it to him unsolicited”.

The police investigation into Niinami is continuing, but Suntory said that “strict compliance with laws and regulations is fundamental” for its senior executives, who are expected to exercise “appropriate caution” when buying supplements.

“Therefore, without waiting for the outcome of the investigation, the company determined that Takeshi Niinami’s actions, which demonstrated a lack of awareness regarding supplements, rendered him unable to continue in the key position of chairman and chief executive officer,” Suntory said in a statement.

“Following discussions with Takeshi Niinami, he offered his resignation of his position due to his own reasons, which the company accepted, effective September 1.”

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The company added that it “deeply apologises for the concern and inconvenience this matter has caused” to its customers and its 40,000 staff around the world, including about 1,200 in the UK.

Suntory was founded in Osaka in 1899 by Shinjiro Torii, who wanted to bring western-style liquor to Japan. His grandchildren and great-grandchildren still sit on the board of the directors.

It has grown to become one of the world’s biggest drinks groups, owning brands such as Orangina, Maker’s Mark and a range of Japanese whiskies.

Niinami, a fluent English speaker who joined Suntory in 2014, is an influential business figure in Japan. He has served as economic adviser to several Japanese prime ministers and is the chairman of the powerful Keizai Doyukai business lobby.

Nobu Torii, Suntory’s president and Shinjiro’s great-grandson, said at a press briefing in Tokyo that it was “a real shame we couldn’t continue as a team” with Niinami, adding: “He was a bold, decisive leader that got things done and I truly respected him.”

Japan is known for its strict drug laws and last year raised the potential prison sentence for possession of cannabis to seven years.

Shortly before that change, Olympus Corp, the multibillion-dollar Japanese maker of endoscopes, sacked Stefan Kaufmann, its chief executive at the time, after an allegation that he had purchased illegal drugs. He was given a suspended sentence in December.