A cat which was locked up behind bars after trying to smuggle drugs and SIM cards in to inmates has reportedly escaped.

The feline was detained at Welikada Prison in Sri Lanka last week.

When it was caught, the animal had two grams of heroin, two SIM cards and a memory chip hidden in a plastic bag tied to its collar and so the animal was locked up by prison guards.

But when they went to feed the animal in the room where it was being kept locked up on Sunday morning only to discover it had mysteriously escaped, the Aruna newspaper reports.

The newspaper said an investigation has been launched to find out to which inmate the cat was delivering heroin.

Authorities detained the animal after discovering it had been trying to smuggle the items into the prison

The prison has reported an increase in incidents of people throwing packages of drugs, phone chargers and mobile phones over the walls in recent weeks.

It's not the only naughty cat to hit the headlines recently.

A cute cat burglar was nabbed as it tried to make a break for it with a bundle of cash stolen from a Russian pub last month.

The animal is believed to still be at large

The money was grabbed from the cash box at the USSR Beer Pub in the resort town of Anapa in the western Russian region of Krasnodar Krai by the kitten after it was adopted by the owner who found it in a box on the street.

CCTV images show the young cat trying not just once but twice to make off with a bundle of banknotes.

The owner of the pub, Nadezhda Vodolazskaya, 37, said that the first time the kitten tried to steal the money, it was noticed by one of the visitors who managed to grab the money back from the feline when it accidentally dropped it on the floor.