AN investigation has been launched after a gang of around 10 men was seen collecting pacific oysters from low water in West Mersea.The men and women were observed taking orders and filling large plastic crates before heading back to shore after three hours work while the tide was out.

AN investigation has been launched after a gang of around 10 men was seen collecting pacific oysters from low water in West Mersea.

The men and women were observed taking orders and filling large plastic crates before heading back to shore after three hours work while the tide was out.

They then carried the crates from the water's edge into three vehicles and left the town.

Yesterday fears were voiced not only that a “gangmaster” could be operating in Essex but that also the shellfish - not taken from a monitored oyster bed and not subject to purification - could be potentially dangerous to eat.

One witness, who was working on the beach about a quarter of a mile from where the men were, said the incident began on Mondayat around 11.30am.

“There were about 10 of them. There was obviously someone in charge, walking backwards and forwards,” he said.

“They had big plastic boxes that looked very heavy. It took two people to carry them.

“When the tide came in they did too and they got into two cars and a people carrier.”

Fish merchant John Jowers, also a Colchester borough councillor, said: “I have called for an inquiry into this.

“Not only is it potentially perilous for the people –there are obvious parallels with the tragedy at Morecambe Bay – but those oysters could be dangerous to eat because they have not been purified.

“Normally oysters like that require 48 hours of ultra-violet purification in a special plant, which is constantly monitored.

“If somebody ate one of those oysters and was ill it could discredit the genuine local oyster industry.”

Colin Daines, the environment protection services manager at Colchester Borough Council, said an investigation into the incident was taking place.

“Eating an oyster which has been picked up from anywhere is obviously dangerous because there is no guarantee it will not be polluted.

“Oysters live by sucking water through their body, and if the water is polluted there could be a risk of infection.

“I would never consider eating an oyster without knowing its origin – shellfish are notorious for causing stomach upsets.

“However, with the proper oyster fisheries, which use thorough monitoring and purification, you can be sure you are safe.”