As much as �300m may have been wasted on a controversial police radio system by ministers, MPs have warned.

Police forces wanted cheaper more localised systems.

But the government chose the national digital Airwave network at a cost of �1.5bn over 19 years.

Police require a sophisticated radio system that can operate across force boundaries

Home Office Minister John Denham

But now Parliament's spending watchdog says the system may not bring the predicted benefits.

"Airwave might be more sophisticated and expensive than it really needs to be," the Commons Public Accounts Committee said.

The new system will allow different police forces to communicate with one another but will not allow officers to contact firefighters in their own area.

It estimates Airwave will cost an extra �300m than a series of regional systems.

"It is significant that individual police authorities and the fire service cited the cost of Airwave as their reason for being unwilling to subscribe to it," it said.

Joint systems

A decade ago a Home Office review recommended police and fire services co-operate in buying new radio systems.

"But the emergency services within a particular area or region are still unable to communicate easily with each other during major incidents, and a solution is still a long way off," said the committee.

The Home Office is criticised for failing to compare prices of systems.

The government has also faced legal challenges over the siting of new masts.

But MPs said the main health concerns seemed to be about "existing analogue systems than with digital systems".

MPs also said there had been no research to see how much officers needed to communicate off their patch.

Health fears

But Home Office Minister John Denham said the new radio system was a valuable tool.

"Criminals do not respect force boundaries and the police require a sophisticated radio system that can operate across force boundaries to combat crime in the modern age," he said.

He questioned whether regional systems would have saved �300m.

"Neither the Home Office nor forces would endanger officers health by introducing dangerous equipment.

"Independent experts have concluded it is unlikely that Tetra, the technology which Airwave is based on, poses a risk to the health of users".

But should there be any health and safety concerns immediate action would be taken.