Police officers have been told to pay back thousands of pounds in benefits after a blunder by their force. One officer has received a demand for £24,000.

The debacle involves rent allowance which is received by about 500 of the Sussex Police's 3,000 officers.

Several claimed they should have received bigger allowances over the past ten years.

The force accepted their argument and the officers received lump-sum settlements six months ago.

This week the force backtracked and sent them letters saying they were not entitled to the increases and demanded the cash back.

Most have already spent the money on new cars, holidays, paying off debts and home extensions.

The Sussex branch of the Police Federation is furious and is seeking legal advice.

Graham Alexander, branch spokesman, said: "This is one almighty cock-up - and what a marvellous time of the year for the force to do it.

"This issue was settled in good faith, the money was paid out and now they are saying they got it wrong and want the money back.

"It's a total lash-up and we are urgently seeking legal advice."

Problems began in 1990 when non-taxable rent allowance was replaced with a new, taxable, housing allowance.

Those on the old system were put on the non-taxable "transitional rent allowance" and if they divorced or separated, they had their allowance cut.

If they remarried they were put on the new housing allowance.

It is taxable and worth less than the transitional rent allowance.

In February 2000, a South Yorkshire officer won a court fight that he should have been entitled to full transitional rent allowance when he remarried.

South Yorkshire Police switched him to the transitional allowance and reimbursed him with the allowance he should have had, plus interest.

As a result, about a dozen Sussex officers in similar positions made claims and the force paid up.

But Sussex Police have now received new legal advice.

A force spokesman said: "These officers should not have been paid and we are now negotiating recovery of the money.

"A number of UK forces are affected by this problem. There are other outstanding claims which have not yet been settled.

"What has become clear is that each case has to be individually assessed on its own merit and this will involve a great deal of work in the coming months.

"Staff associations have been consulted throughout and the Police Authority is being kept informed.

"Provision has been made to ensure that any cost to the force will not impact on operational policing nor on decisions over council tax."

The spokesman said the force had a duty to treat staff fairly and to "spend public funds correctly."