At first they blamed absent-mindedness for the spate of missing keys but when ever more sets disappeared residents realised other forces were at work.
Then they discovered the culprit, a genuine ââ¬Åcat burglarââ¬Â who had made off with more than 20 sets of house and car keys.
The neighbours discovered that Milo the neighbourhood moggy was stealing the keys ââ¬â attached to his magnetic collar.
The nine-year-old cat had been fitted with the collar to operate her cat flap and stop other cats sneaking into her home to steal her food.
But the collar was also picking up the keys along with its adventures to other peopleââ¬â¢s homes.
It was not until Kirsten Alexander, 27, spotted her pet coming through the cat flap with a set of someone else's keys dangling from her magnetic collar that the mystery was solved.
In the past five weeks, Milo's collar picked up at more than 20 sets house and car keys as she wandered from home to home through neighbour's catflaps in Stoke Newington, north east London.
Miss Alexander said: I put a magnetic cat flap to stop other cats coming in to steal Milo's food, but I had no idea what she was getting up to all day when I was at work.
Obviously she likes roaming around and sneaking into other people's homes and it just so happens that her magnetic collar kept picking up people's spare keys.
She found 12 sets of keys in her back garden and eight dotted around her home ââ¬â as well as another six sets which were found in neighbour's gardens after they dropped off Milo's collar as she prowled through their gardens.
She said she had also found dozens of metal items scattered around her house, including nails, pins, screws and bolts.
When I saw her coming through the cat flap with a set of keys round her neck I thought 'poor thing' because her neck was really weighed down, and then it dawned on me what was happening,ââ¬Â she said.
I've given all the keys back and luckily neighbours have seen the funny side of it.
