A Yeadon inventor hopes to turn crime-fighter after creating a security system that shoots blank gun cartridges to scare off potential thieves.

David Auty, from Rufford Avenue, manufactured the Site Sentry after friend Stuart Petit complained about the number of thefts he was having.

Mr Petit, from Rawdon, breeds and shows horses and keeps them on land in Bramhope.

But after being targeted by thieves who have stolen thousands of pounds of property, he asked Mr Auty for help.

Six months later and Mr Petit has a fully operational Site Sentry on his land, which has already proved its worth.

Now Mr Auty has had more than 150 of the systems made, and he hopes that people will find the Site Sentry a hit - especially farmers and people with outdoor property.

Mr Auty, 54, said that Mr Petit wanted something to frighten thieves off before they reached his property.

He said: "Stuart has no electricity, and he said he wanted something especially for outdoor use, so I said that I would put my thinking cap on and I set to work messing about with bits and pieces.

"I looked at poaching alarms and thought how can I improve on the basic premise to make an alarm that is safe and easy for people to use and could not be seen as any kind of weapon.

"I made a working prototype from a cash box and a copper pipe. A ball bearing placed inside falls and triggers the cartridge if it is disturbed.

"This is a serious security product which is extremely well engineered, made totally from stainless steel, is durable, portable and does not need electricity."

Mr Petit, who travels around the country showing horses with his family, has suffered at the hands of thieves who have stolen a lorry, horsebox, horse rugs and saddles and even horse feed.

He said: "David's invention is absolutely marvellous, I really can't thank him enough.

"After he had done the first Site Sentry, he invited me over and told me to touch it. "There was such a huge bang, I was frightened to death, but it is totally safe and it is very effective.

"We have already heard it going off and it has been successful so far. I wish David the best of luck, I think he will do really well with this invention."

Years ago Mr Auty invented an air powered steering system for vehicles which could be attached after purchase at a fraction of the manufacturers price.

Numerous heavy goods vehicles companies used the invention before vehicle manufacturers changed their ideas.

He has also invented a remote controlled vehicle which could be used in dangerous or difficult areas.

A Japanese company used the driverless vehicles for a number of uses including grass cutting in areas which could be dangerous for workers or that were difficult to get to.

Anyone interested in the Site Sentry, which costs £199, can call David Auty on 0113 2509788 or email him at Perimiter Security Devices at davidpsdltd@aol.com.