NSW farmers are turning into backyard detectives and using security cameras and mobile phones to stop a rise in farm fuel and equipment thefts.

Hidden infrared cameras and alarms are being installed to snap images of criminals and suspicious vehicles.

As fuel prices soar, a surge in rural diesel thefts has seen hidden cameras being hooked up to fuel tanks, machinery, trucks, property gates, trees and houses.

The cameras also keep a big brother watch on everything from cattle to vacant buildings.

About 20pc of the cameras and monitoring devices sold by surveillance equipment supplier, Farm Cam, have been installed to combat fuel theft from machinery or tanks, managing director, David Sanders, said.

His business sells mostly to rural areas.

“We get people who have lost $40,000 in diesel, and it might have happened on a regular basis,” he said

“Paying $1,000 or $2,000 for a camera is peanuts to that.”

Pig hunters cutting fences and leaving gates open were a big problem, too, but he said the surge in security consciousness among farmers was primarily due to more people realising their properties were sitting ducks for potential crime.

“You can roll up with a big tank and pinch 1,000 litres of fuel and chances are the farmer is never going to realise he has lost it.”

Farm Cam sells between 100 and 150 cameras monthly and thousands are already working in the bush, with police and councils also increasingly using the devices for undercover investigations.

Dates and times can be imprinted on the images, which have been used in criminal court cases.