A Russian-owned tanker has been held in South Korea in a probe into alleged illegal transfers of oil to North Korea.
The vessel was named as the 2,000-dwt Katrin (built 1987), flagged in Panama, according to the Yonhap news agency.
It is docked in Busan.
The ship's owner, a Russian national, is denying the allegations.
It was inspected twice in joint operations undertaken by South Korea's spy agency and customs office in February when it entered Busan for maintenance.
