SURVEILLANCE powers designed to tackle terrorism have been used by councils in the region more than 500 times for offences as minor as dog fouling, littering and trespassing.

Darlington Borough Council alone has used the Regulation of Investigatory Powers Act (Ripa) 154 times to investigate alleged offences including racist abuse and benefit fraud.

The Liberal Democrats, who obtained the figures, said that they represented a fresh erosion of civil liberties and warned that Ripa was becoming a “snoopers’ charter”.

The study showed that Ripa powers have been used 527 times in the region since 2004.

Alleged offences included unauthorised use of a vehicle for private hire, anti-social behaviour and benefit fraud.

Several councils also used the powers to conduct internal investigations, including Ryedale District Council, in North Yorkshire, which used the act to conduct five operations investigating suspected dishonesty by staff.

According to the figures, seven officers at Darlington are authorised to use the powers.

In the past five years, the council has used the act 91 times to investigate allegations of noise nuisance.

A council spokesman said: “The council has a Ripa policy which is available for the public to see on the council’s website.

“Any council officer applying Ripa powers will have undertaken the appropriate training and will follow the guidance in the policy.”

Easington District Council used the powers 46 times in the past five years, for alleged offences that included benefit fraud and littering.

Keith Parkinson, the council’s environmental health manager, said: “Councils will use surveillance when the situation warrants it, often to prevent fly-tipping or serious cases of dog fouling or littering.

“It will only be part of a package of measures that include education and warning signs.”

Lib Dem local government spokeswoman Julia Goldsworthy said that when Ripa originally became law, only nine organisations – including the police and security services – were allowed to use it.

That has since been extended to 795 groups.

She said: “We are now in a situation where dog fouling is considered enough to warrant surveillance by council officials.

“Unless Ripa is reformed, it risks becoming a snoopers’ charter.

“Surveillance powers should only be used to investigate serious crimes and must require a magistrate’s warrant.”