The Coast Guard recovered around 4,000 litres of illegal fuel oil during an operation in Daulatkhan upazila of Bhola on Monday night.
The seizure was made in the Meghna River near Chokighat area under Daulatkhan upazila, according to officials.
Media officer of Bangladesh Coast Guard South Zone Lt Commander Sabbir Alam Suzan confirmed the matter.
Coast Guard officials said acting on a tip-off, a team conducted a drive in the Meghna River and searched a trawler, recovering the fuel oil.
Sensing the presence of law enforcement, the people on board the vessel managed to flee the scene, leaving no arrests.
Later, a mobile court led by Daulatkhan Upazila Assistant Commissioner (Land) Shaon Majumder Suman sold the seized fuel at market price and deposited the proceeds into the government treasury.