Bradford Council has been branded a "Big Brother" authority for allowing more and more of its CCTV cameras to be used in so-called "covert" police and customs investigations.

Figures obtained by the Telegraph & Argus under the Freedom of Information Act show Council officers approved more secret surveillance operations in the last year than they did in the previous four years combined.

Just 13 incidents of undercover filming were approved between 2000 and 2004, but there were 17 last year.

Fifteen requests came from the police and two from Customs and Excise. The former chairman of Bradford Council's community safety sub-committee, which oversaw the network's installation in 1990, is outraged and has called for discussion on the issue.

Councillor John Ruding (Lab, Tong) said the system was never meant to be used in this way: "We are beginning to be 'Big Brother' to the community of this district and we were never elected to be that," he said. "We are not MI5 or the police; they have cameras of their own."

Coun Ruding said it was unacceptable that an officer can make covert use of the Council's CCTV without any elected member being involved.

"I will discuss the issue as soon as possible with the chairman of the safer and stronger communities improvement committee with a view to getting a cross-party view on this," he said.

"If we undertake CCTV operations on the community, the council tax payers are not only likely to be the victims of it, they are also paying for it and they have the right to expect a proper procedure."

Bradford Council said all requests from agencies like the police are legal and Phil Holmes, the authority's CCTV manager, claimed the filming was not truly covert because all Council cameras are publicly sign-posted.

He referred to the technique as "directed surveillance" - cameras which are already in place and are used to temporarily target a premises or an individual. He said: "We are not 'Big Brother'. Our views are that we provide a service and we protect the community; we are not spying on people."

Detective Inspector John Armitage, based in Bradford South, said Government legislation and human rights laws are borne in mind whenever asking for the Council's help.

"It would seem a nonsense to put our own systems there when the Council already has its own facilities up and running," he said. "We have a finite amount and we would have to bring them over, site, maintain and monitor them."

Commenting on the rise in requests, he said: "CCTV is something that has come on in leaps and bounds in recent years and officers' knowledge of what is available to use has also increased."