Police on Thursday detained a 31-year-old woman related to the founding family of a major South Korean dairy producer on suspected drug use.

Hwang Ha-na was taken into custody this afternoon from a hospital where she was staying for treatment in Seongnam, south of Seoul, the Gyeonggi Southern Provincial Police Agency said.

A handcuffed Hwang, covering herself in an orange hoodie, black sunglasses and a mask, arrived at the police agency at around 3 p.m.

Hwang is a granddaughter of Hong Du-yeong, the late honorary chairman of Namyang Dairy Products Co. who founded the company.

She's also known for her active Instagram postings and her past relationship with K-pop boyband JYJ's Park Yu-chun.

Police are investigating her over suspicions that she avoided being charged for drug use in a 2017 police probe because her family pulled strings to exclude her from the investigation.

She was accused of selling 0.5 gram of methamphetamine to a person and also using the illegal substance herself in September 2015.

The Jongno Police Station referred her case to the prosecution recommending a non-indictment, citing a lack of evidence.

Prosecutors later dropped all charges against Hwang. (Yonhap)