Homeowners are facing a potential plunge in the value of their properties because of their postcode.

Experts have today identified 25 boom areas which are most at risk from a slump in prices.

Saltdean, in Brighton - postcode BN2 - is 12th most at risk from a drop, according to credit agency Experian.

The average home costs £148,075, up 25 per cent on last year's prices and 162 per cent since 1995.

Parts of Crawley and Uckfield also appear on the at-risk list, coming in at eight and 21 respectively.

House prices in Brighton and Hove have soared in recent years, nudged upwards in part by the South-East commuter boom and the successful city status bid.

Young families and people starting their careers have taken out huge mortgages to enable them to buy in boom areas like Brighton.

If prices fall, some could be forced into negative equity.

In Langley Green, postcode RH11, the average house price is £133,135, up 35 per cent on last year and 169 per cent since 1995.

Homes in Uckfield - postcode TN22 - cost an average of £237,773, up 49 per cent on last year and 139 per cent since 1995.

Experian, used by banks and building societies to run credit checks, said the "property mania" was unsustainable. It warned a "correction" of up to ten per cent could affect the 25 districts.

This would see house prices fall by up to £15,000 in Saltdean, £13,000 in Langley Green and £23,000 in Uckfield.

Experian spokesman Bruno Rost said: "The current property mania cannot continue. The economy is struggling and people in some areas appear to be paying over the odds."

However, Andy Lees, president of Brighton and Hove Estate Agents Association, said: "Frankly I'm astonished Saltdean has been singled out because I can't see anything to suggest it is any different from other areas of Brighton at the moment.

"There is a good market in Brighton and Hove and where these people get figures to say prices are going to drop by 'X' amount I really don't know."

Mr Lees, a residential partner at Brighton-based Graves Jenkins, added: "Brighton has tended to follow London and they have been achieving some very good prices of late.

"We're hoping the rail link is going to improve and if that happens then Brighton's popularity will continue."