A con man who tried to sell a laptop bag containing bottles of water to an off-duty policeman has been convicted.

Brian McDonagh, of Hillfield Avenue, Edgware, was given a four-month suspended sentence, a curfew and a fine at North West London Magistrates Court.

The 34-year-old approached his victim - without realising he was an off duty detective - in High Street, Edgware, and offered to sell him a laptop, a tablet and a mobile phone.

The quick-thinking officer realised it was part of a scam in which the fraudster offers a genuine laptop for sale then swaps the bag around for an identical one containing bottles.

He decided to gain further evidence before calling the police, and McDonagh was arrested by Greenhill Safer Neighbourhoods Team on November 2013.

After searching his car, they found a laptop and iPad inside a laptop bag, and an identical laptop bag of similar weight containing water bottles.

As well as his sentence, he was ordered to pay £85 in costs and a victim surcharge of £80.

Despite professing his innocence he was taken to Harrow Police Station where he was charged with possession of articles for use in fraud.

PS Jamie Kay said: "The quick thinking of the off-duty police officer secured the conviction in this case, as did the thorough investigation by my officer PC Joe Nanglegan.

“I would urge people to be cautious when buying property on the street at a price that seems too good to be true and I would encourage suspicious activity to be reported to the police."