A major oil smuggling case has been referred to the First People's Procuratorate in Southern China's Hainan province for review and prosecution.

Coast guards caught an oil tanker and four fishing boats reportedly smuggling refined oil in waters off east Wenchang, Hainan, on April 22, according to the China Coast Guard. 21 suspects were detained, and 4,730 metric tons of refined oil were seized at the scene.

It is one of the largest amount of refined oil seized by China Coast Guard.