SEOUL – The South Korean police searched Starbucks Korea’s headquarters in Seoul on Aug 5, Yonhap News reported, as part of an investigation into a marketing campaign that has become one of the country’s biggest recent corporate public-relations crises.

The raid by the Seoul Metropolitan Police Agency came months after the coffee chain’s “Tank Day” promotion was accused of insulting victims of South Korea’s democracy movement, Yonhap reported, citing the police.

Civic groups say the campaign mocked the victims of the highly sensitive May 18, 1980, Gwangju uprising in what they described as a misguided attempt to sell beverage tumblers.

The controversy erupted in May, when Starbucks Korea promoted discounts on its “Tank” tumbler collection, with civic groups claiming the language in the marketing push evoked military tanks used to suppress pro-democracy demonstrators.

Starbucks withdrew the promotion within hours and top executives apologised, while police launched an investigation, Yonhap reported at the time.

Calls to the Seoul Metropolitan Police Agency went unanswered on Aug 5. Shinsegae Group, which owns a controlling stake in Starbucks Korea, did not immediately respond to a request for comment.

The incident sparked quick backlash and snowballed beyond social media, exposing the risks for Starbucks’ largest market outside of the US and C...