Environmental campaigners test results showing beaches are clean mask a risk of illness from sewage.

Tests carried out by the Environment Agency show all 26 Sussex beaches within the Southern Water region meet a European bathing water directive.

Seawater passed the test at 99 per cent of beaches - compared with 41 per cent in 1988, before Southern Water began a multi-million pound environmental improvement programme.

Beaches include West Wittering, Bracklesham Bay, Selsey, Pagham, Littlehampton, Worthing, South Lancing, Southwick, Brighton and Hove, Eastbourne, Pevensey Bay, Hastings, Birling Gap and Newhaven.

The results showed that 54.4 per cent of the bathing waters were of an excellent standard, with water quality 20 times higher than the minimum category of 'good'.

However, environmentalists say not enough beaches met the higher standards.

Campaign group Surfers Against Sewage said its survey showed bathers became sick at beaches which met the mandatory standard.

Of the 800 cases on its medical database for the South Coast, 74 per cent of the illnesses were contracted at Government-passed beaches meeting the mandatory standard.

That standard was 20 times lower than European recommended guideline.

Richard Gregory, director of the national Surfers Against Sewage, who lives in Brighton, said: "How can we have any faith in that standard when our reality has shown us that it's not good enough?

"Southern Water use customers' money to build and operate their sewage treatment plants. We would therefore ask that our money be invested in the best available technology that focuses on the real issue of sewage treatment and disposal, the removal of harmful viruses and bacteria.

"We are glad to see that 54 per cent of beaches in the region are meeting the higher guideline standard and look forward to the day when that figure reaches 100 per cent.

"It doesn't matter what they might say in terms of tests that have been carried out. As a surfer, you know that when the water tastes like petrol and detergent and makes you feel ill, you know you are in sewage."

John Spence, Southern Water's asset manager, said: "The results show the benefits of our coastal improvement work during the last ten years.

"However, we must remember there are still many factors not within Southern Water's control which can affect bathing water quality, such as surface water run-off, discharges from boats and even animals on beaches."