A bungling thief tried to escape with a crate of beer - only for a brave female shopkeeper to lock him inside.

The crook, who was wearing a flannel shirt and a baseball cap, entered the Bottle-o Beechboro store in Perth, Australia, just after 11am on Tuesday. He grabbed a 12-pack of drinks and headed for the exit.

However, quick-thinking cashier Kellie Gordon pushed an automatic look so the sliding doors wouldn't open.

‘He came to the counter like he was pretending to get served and just made a run for it,' Kellie said.

‘He didn't seem aggressive so I wasn't concerned. It was more of a defeat, more than anything.'

The would-be thief tried to pull the doors open, but they were held shut by a magnet operated by the store attendant who sat calmly behind the counter.

The man then tried to run around the counter, but the attendant blocked his way. He then gave up and returned the drinks to the counter.

The man then fled the store and Kellie called the police, but the man was not caught.

The police are still investigating the incident and have appealed to locals to help identify the suspect.