bangkok: a sea turtle dubbed 'piggy bank' has had her fortunes restored after thai vets removed 915 coins from her stomach -- a deposit built up after years of gulping down good luck pennies tossed into its pond.

the 25-year-old turtle, called 'omsin' in thai, underwent a gruelling seven-hour surgery on monday to remove the five kilogramme hoard of coins.

she was sent to bangkok vets with a cracked shell and an x-ray unexpectedly revealed the haul, which came in various currencies.

"there were 915 coins in her stomach, we removed them one by one," said nantrika chansue, a veterinarian in charge of chulalongkorn hospital's aquatic research centre told afp.

"piggy bank is okay now but she will have to remain at the centre for up to two weeks," the vet added, saying it was the first surgery of its kind.

the troubled reptile lived for two decades in a small public park in chonburi province.

visitors tossed coins into her pond seeking to 'make merit' or good luck, a practice vets have urged the public to stop.

"a turtle can live up to 80 years and the belief is that throwing coins into the turtle pond will make the coin thrower live longer," rungroj thanawongnuvej, dean of the faculty of veterinary science at chulalongkorn said in a statement.

"throwing the coins is more bad karma because it is animal torture," he said.