The BSC ship MT Banglar Shourav caused oil spillage at the channel water from Friday night and port officials detected it the next day when it was anchored at the dry-dock jetty for repair.Black oil spilled over from it and fouled over a 15 km expanse of water at the confluence of the Bay and the Karnaphuli river.

High officials of BSC visited the vessel and the river channel yesterday.

A two-member committee headed by the assistant harbour master of CPA Faridul Alam was also formed to investigate the incident.

"We have already observed the negligence of the officials in handling the 17-year old oil tanker engaged for carrying crude from mother vessel anchored at the outer port," Alam said.

"We are collecting relevent evidence from the vessel and affected port channel," Alam said adding "we will submit the report within two days and the responsible persons will not escape legal action."

The magistrate of CPA Munir Chowdhury said initially a case was filed against the ship.

"Further legal action will be taken after receiving the investigation report," he added.

"I myself went to the ship and visited the river channel where I found huge oil slicks floating on water," he said.

Port officials said the leak was later wedged to check the spillage of fuel through a weak valve of the vessel.

They also informed that four boats were hired to lift the oil slicks with cans while some flowed away by the river current.

A member of CPA (operation) Kamrul Hossain said, "We have surveyed the river channel once again today. We did not find any fish dying from the oil spillage".