An £80m programme to roll out mobile phones to frontline police officers has left some forces with more mobiles than officers and others with just one BlackBerry or PDA between 100, auditors said today.

Just one in five forces have used the devices effectively, and not enough consideration was given to how they would be used, how much local spending was required, or how realistic deadlines were, the report from the National Audit Office (NAO) said.

Despite the scheme providing basic benefits, including some officers spending an extra 18 minutes a shift out of the station, this varied significantly and "value for money has not yet been achieved", it said.

While most forces agreed that mobile devices gave their officers some extra time out of the station, in some cases officers were spending more than an hour-and-a-half extra in the station and away from the public each shift.

A review of the scheme also found that some forces only had devices available to 1% of officers, while in others this rose to 151%.

In all, 19 forces had devices available for less than half of their officers.

The NAO survey of 32 of the 43 forces in England and Wales also found more than two thirds (22) cited drawbacks with mobile technology projects, with only a third (10) claiming "cashable savings" which were relatively minor.

The report said the "experience of implementing mobile technology reinforces the challenge of achieving convergence of ICT".

It comes after the Home Secretary announced last July that a company owned and led by police chiefs would be set up to reform the "confused, fragmented and expensive" way in which forces use computer systems.

Theresa May said the current system was "broken", with 5,000 staff working on more than 2,000 different systems across 100 data centres.

The firm will aim to cut the £1.2 billion annual spending on ICT and free chief constables from having to spend so much time addressing such issues.

Amyas Morse, head of the NAO, said while the roll-out of mobile technology was achieved against "a tight timescale and at reasonable cost", "too little consideration was given to the need for the devices or how they would be used".

"In the majority of forces, the benefits have not so far extended beyond simply allowing officers to spend more time out of the station," he said.

"There is still the opportunity to achieve value for money, though, if more forces use the technology to improve the efficiency of their processes and make savings in their back-office activities."

Margaret Hodge, chairwoman of the Commons Committee of Public Accounts, said: "The business case for investing in mobile technology did not consider if local forces were prepared for the programme or if there was the capability and capacity to introduce it.

"The report highlights the challenge of making changes to technology across a police service that has 2,000 separate and bespoke ICT systems."

She went on: "If value for money is to be achieved, mobile technology will need to be used to drive improvements that will reduce paper work and make police work more efficient."