South Korean star Yunho of TVXQ fame - the boyband had topped the charts in Asia in the early 2000s - is under investigation for violating safe distancing measures.
The 35-year-old singer-actor had allegedly remained with three friends in a restaurant in the Gangnam area until midnight in late February, even though Covid-19 regulations in Seoul only allowed restaurants to operate until 10pm.
After it was reported on Tuesday (Mar 9) that he was under investigation, he posted an apology on Instagram the next day.
"I am very sorry to the healthcare workers who are working hard and dealing with a difficult situation due to Covid-19 and to everyone who has been going through difficult and tiring days," he wrote.
"I am very ashamed and angry with myself for being unable to abide by the business hour restrictions when meeting with my friends and spending time talking with them, and many people must also be angry and upset by my wrongdoing."
TVXQ, which began in 2003 as a quintet, is now a duo, with the other member being Max Changmin. The other three members split off after contractual disputes in 2009.
The group sold more than 10 million records in their first 10 years and are regarded as one of the most successful music acts of their generation.