Pictures of the Betta fish, with its blue, red and white horizontal stripes replicating the Thai flag, went viral after its breeder Kachen Worachai posted them on a private auction group on Facebook.

He said he had expected someone to buy the fish for a few thousand baht and was shocked when the bidding hit 10,000 baht on the second day.

"I never expected my fish to go for this price," said Mr Kachen, a 40-year-old convenience store owner who breeds Betta fish as a hobby.

He posted the pictures on November 6 with a starting bid of 99 baht and closed the auction on November 8.

Betta breeders have previously attempted to reproduce the colours of the Thai flag but none have come close.

The highest previous price was for a half-moon Betta fish which sold for 23,500 baht.

"The chance of getting a fish with the flag's exact colour is like one in 100,000," said Mr Kachen. "So many people have tried to breed the Thai flag colours. Luck was really on my side."