A notice posted outside a Starbucks sotre in Seoul, Wednesday, informs customers of an early closure on June 22 due to company's mandatory histroy education for all employees. Yonhap

Police said Wednesday they were questioning the head of Shinsegae Group's audit team over allegations that its affiliate Starbucks Korea insulted victims of the 1980 pro-democracy movement in Gwangju with its controversial marketing campaign.

The Seoul Metropolitan Police Agency called in Yang Jong-hwan to question the results of the group's weeklong internal inspection of the incident in May.

Starbucks Korea, operated by E-Mart Inc., launched an online "Tank Day" promotion on May 18, the anniversary of the 1980 Gwangju pro-democracy movement.

The coffee franchise launched a discount event for "Tank" tumbler sets, along with the controversial phrase, "Put it on the table with a sound of 'Tak!'"