POLICE are threatening to cut off accidental mobile phone calls in order to ease demands on the force's 999 emergency system.

Control room staff at Durham Police headquarters at Aykley Heads, Durham City, have been told to terminate so-called ghost 999 calls from mobiles to avert what has been described as a "potential call-handling crisis".

Research predicts that during this year the amount of emergency calls could hit a record 70,000 - a leap of more than 20 per cent on the previous 12 months.

Calls handled by Durham's control room jumped to 61,657 in 1999-2000, compared with 50,608 in the previous 12 months.

As many as 9,000 ghost calls from mobiles - often caused by accidental dialling - are expected to be received this year.

Police chiefs said staff are coping with the increased workload, but fear accidental mobile phone calls could affect responses to emergencies.

A Durham Police spokesman said: "At present, when a silent 999 signal is received from a mobile and no one responds to any questions, control room specialists take all reasonable steps to try and trace the call.

"The process can sometimes take up to half an hour, despite the fact the chance of locating the phone user is remote.

"In future, under new procedures, the control room specialists will terminate the calls unless there is some obvious or particular cause for concern."

Meanwhile, North Yorkshire Police said staff were dealing with up to 200 accidental mobile phone calls a month.

A spokesman said: "Operators are having to answer these calls, which add up to a waste of time and could stop a genuine call coming through, which could be potentially life threatening."

And while Cleveland Police said mobile phones were not causing any serious problems, a Northumbria Police spokeswoman said they were seeking to tackle nuisance calls by working with BT to find a solution.