It takes a lot to shock residents of outback Queensland mining towns, but having an early-morning swim with crocodiles in the pool may just have done the trick.

Things became very lively in the sometimes sleepy north Queensland city of Mt Isa, when a swimmer found a crocodile near the pool before his morning laps. The facility was quickly evacuated and another eight baby crocodiles were found in and around the water.

Pool manager Brian Rodriguez said it was one of the stranger complaints he has had.

“He said 'Brian I don't mean to alarm you but I think there's a crocodile in the pool',”Rodriquez said.

“We got everyone out of the water and we ended up finding five baby crocs swimming around.

“Then we found another two wandering around on the concrete after that as well.”

The owners of the outback aquatic centre say they have reviewed CCTV footage from the night before, and now believe that the reptiles were dumped in the water as some kind of joke or prank.

The baby crocodiles, each less than 30 centimetres long, were taken out of the chlorinated pool and allowed to swim in a tank normally reserved for some resident turtles. Tragically, however one crocodile did not survive its day in the sun.

Local snake and reptile handler Gavin Lawrence has taken custody of the young reptiles and says after a nourishing meal of fresh tadpoles, he will release them back into the wild.