The cash, wrapped in an Asda carrier bag, had been stolen earlier and left in the toilet pan by the thief.

But the thief had a pang of conscience and went back to retrieve the cash, intending to return it to its owner.

South Yorkshire Police say that when he went back, the bag and cash had been removed by another visitor.

A spokeswoman for South Yorkshire Police said the original thief had had second thoughts: "He obviously realised he'd done wrong and contacted the police".