So, just what attracts a mild-mannered tabby to a life of crime?

The answer, if you look closely, is the magnet hanging from her collar.

This is Milo, the cat burglar responsible for pinching more than 20 sets of keys from her neighbours in the past month.

Her unsuspecting owner Kirsten Alexander had no idea of Milo’s other life until she caught her coming through the catflap with the evidence jangling around her neck.

And it was only when she found a collection of keys dotted around her house and garden that she realised the extent of the crime spree.

Miss Alexander, a 27-year-old office worker, had fitted Milo with a magnetic collar to automatically unlock the catflap at her home. This stopped other cats from slipping through and eating Milo’s food.

What she didn’t realise was that Milo had also been making herself at home at the neighbours’ houses, which didn’t have her sort of high-tech protection.

Slipping through their cat flaps, and skulking through their rooms, she picked up all manner of things thanks to the magnet in her collar.

Most of them were keys.

At first neighbours in Stoke Newington, North-East London, thought they were misplacing them but last week they started putting two and two together when they realised there had been a spate of thefts.

The game was finally up when Miss Alexander caught Milo arriving home with her latest haul.

A search produced 12 sets of keys in the back garden and eight dotted around her home – as well as another six sets in neighbours’ gardens.

She also unearthed dozens of metal items scattered around her house, including nails, pins, screws and bolts.

‘I had no idea what she was getting up to all day when I was at work,’ she said.

‘Obviously she likes roaming around and sneaking into other people’s homes and it just so happens that her magnetic collar kept picking up their spare keys.

‘I’ve given all the keys back and luckily my neighbours have seen the funny side of it.’