A NEW police radio system pioneered in Lancashire is "unlikely" to pose a health risk to officers, a report reveals.

The National Radiological Protection Board (NRPB) report said no health hazard from the digital TETRA radio system had been identified.

The radios went on trial in Lancashire in February before being introduced across the country.

Last summer's Stewart Report into mobile phone safety urged caution with radio equipment operating at or near 16 hertz -- TETRA operates at 17.6 hertz.

Earlier studies had suggested when radiofrequency (RF) signals were modulated at around 16Hz there could be biological effects on the brain and other tissues, possibly inducing cancer.

The Government asked scientist Sir Richard Doll, chairman of the NRPB's advisory group on non-ionising radiation, to investigate all the available research.

In his report today Sir Richard said earlier findings were contradictory.

He concluded: "Although areas of uncertainty remain about the biological effects of low level radiofrequency radiation in general, including modulated signals, current evidence suggests that it is unlikely that the special features of the signals from TETRA mobile terminals and repeaters pose a hazard to health."

A Lancashire Police spokesman said: "We welcome this report and we would reiterate the point that we would never put our officer at risk.

"This new system has many operational benefits. It prevents people from being able to scan signals and listen to us. A lot of criminals have scanners and by preventing them from listening to us we will be able to make things more difficult for them.

"The public will be able to call their community officer direct and they will be able to contact residents direct as well."

The TETRA system also gives better reception direct access to the Police National Computer.

The system means an end to calls being routed via the traditional control room. Each handset could feature an emergency button.

Digital technology allows messages to be encrypted, preventing scanning.

If TETRA is given the go-ahead it will be issued to other forces across England and Wales at a cost of £2.5million.