A STORE security guard was head-butted after thwarting a pair of pick-pockets in a Pinner shop.
The Lidl employee approached the two suspects at about lunchtime last Thursday after seeing one of them taking a purse from a woman's handbag.
But as the older of the two suspects, believed to be in his 20s, handed the black and yellow purse back to the guard, he assaulted him before escaping the shop in Bridge Street.
It is believed the suspect had originally passed the victim's purse on to an accomplice - aged about 10 or 11.
The security guard was lucky to escape without any injuries, but an eyewitness, who asked to remain anonymous, was disgusted by the attack.
He said: "I saw a man steal the bag from a woman in the shop and hand it to a young kid, who I assumed was his son.
"Then, the man who looked to be a store detective, approached the guy and got smacked in the face for his efforts.
"I think it's absolutely disgusting that this is what this guy has got for doing his job - and I've heard that this is the second time it has happened in Pinner recently."
Harrow Police are now investigating the incident and will be looking closely at CCTV footage to catch the suspects, who were heard to be speaking in Irish accents.
A police spokesman also said that although rates of pickpocketing had been reduced across the borough in recent months, busy stores and super-markets were still the areas targeted by criminals.
He said: "We continue to urge people to be cautious wherever they shop but we have still seen a number of pick-pocket offences in supermarkets.
"It is very easy to become distracted in busy places so we would always encourage shoppers to be as vigilant as possible."
Lidl spokesman Marco Ivone said: "This kind of behaviour is completely unacceptable and we will work with the police to bring these criminals to justice, and in instances like this we will always prosecute.
"We have security guards and CCTV to protect our staff and shoppers, but instances like this seem to be a problem for everyone everywhere."
Anyone with information should call Harrow crime desk on 020 8733 3441 or call Crimestoppers, anonymously, on 0800 555 111.