A 146,000 ton Hong Kong-registered tanker was hit by a crane while at anchor off the port of Taean, south of Seoul, causing a leak of 15,000 tones of crude oil, reports One News quoting Seoul's maritime ministry.

The tanker "Hebei Sprint" was anchoring near Taean to discharge crude brought from the Middle East at the port's unloading facilities.

"Hebei Sprint" was hit by the crane early on Friday. It is said, that the equipment was in transit after being used to build a bridge in Taean.

Friday's spillage is the largest in South Korean waters since a 5,000 ton crude discharge in 1995 at Yeosu, south of Seoul.