A Kent beach has been hit with a year-long "do not swim" warning after the discovery of unsafe levels of bacteria in the water.

The quality of the seawater at St Mary's Bay on Romney Marsh has deteriorated in recent years and monitoring by the Environment Agency (EA) has revealed heightened traces of intestinal enterococci, found in faecal matter.

As a result of the testing, signs advising visitors not to swim in the sea will remain in place for the 2023 bathing season.

The EA is now working with other agencies to try to establish what has caused the spike in bacteria in the coastal waters which are popular with tourists during the summer months.

Investigators are probing possible sources and the routes through which this pollution may have found its way into the water.

The watchdog monitors water quality between May and September by taking samples at designated bathing sites, such as St Mary's Bay.

It is the only site in Kent where a "do not swim" warning is in force.

An EA spokesman said: "The Environment Agency will continue to work with its partners to fully investigate the reasons for the decline in bathing water quality at St Mary's Bay.

"All agencies involved are working to identify, remove and reduce the sources of the pollution to ensure that the status of this bathing water improves.

"As part of our investigations, we are monitoring several potential sources of pollution including septic tanks, misconnections and potential sources of diffuse pollution."

Samples will continue to be taken at St Mary's Bay during the summer.

If results of these tests show an improvement then the overall classification of the water quality could be upgraded at the end of the bathing season.

However, if bacteria levels do not meet minimum standards then the EA will continue to warn the public against bathing at this location.

The nearest bathing spots along the coast, at Littlestone and Dymchurch, both currently have a "good" rating compared to the "poor" designation for St Mary's Bay.

Issues with water quality at this spot are not linked to ongoing concerns around the Kent coast about sewage reaching bathing waters when storm discharges occur from the sewerage network.

In those instances, which have led to campaigns for improvements by Southern Water, warning against swimming tend to be in place for hours or days.

Last autumn an estimated 2,000 people rallied on Tankerton Beach in Whitstable to voice their anger at the private water utility company.

The "do not swim" warning will come as a blow to businesses in St Mary's Bay, which is a small community south of Dymchurch,.

It is popular with holidaymakers during the summer months, who often stay at holiday resorts along the Marsh coastline.

Local businesses, like independent cafes, are often highly reliant on the trade done in the high-season.

Last year Dymchurch beach was named as the best in the south east in the Sunday Times 50 Best Beaches Guide.