A group of Brazilian lottery players who thought they had won a $US30 million ($33.4 million) jackpot had their euphoria turn to dismay when they found out their precious ticket had not been registered, police said.

Investigators believe the shop where the group of 40 players had bought their ticket did not enter their numbers into the national lottery computer system, invalidating their win.

"We know that the ticket was paid for and if the ticket was not properly issued then fraud was committed," a local police chief, Clovis da Silva, said.

The government financial agency responsible for the lottery has suspended the shop in the southern city of Novo Hamburgo, and the bitter would-be winners are looking at launching a lawsuit.

AFP