Fishermen in the central province of Nghe An on Tuesday morning discovered the carcass of a giant fish weighing around one metric ton.
The carcass, on which no injury was found, was fresh and locals believe that the fish must have just died a few hours earlier.
The 5-meter long fish had a big mouth with small, sharp teeth.
According to some experienced fishers, the fish could be a megamouth shark, an extremely rare species of deepwater shark.
The giant fish is believed to be a megamouth shark.
The fish may have been caught in a shoal and could not escape during low tide.
Megamouths are large sharks, able to grow to 5.5 meters in length.
As their name implies, megamouths have a large mouth with small teeth, and a broad, rounded snout, causing observers to occasionally mistake megamouth for a young orca.