HUGE swathes of plastic washed into St Austell Bay have been branded a "serious marine pollution incident" by a wildlife charity.
Beach users at Carlyon Bay fear that ripped plastic mesh – used under controversial sea defences for the stalled £250 million beach development – has been thrown into the sea and washed up on Par beach.
The ferocious storms have also exposed the plastic netting under the sand, flattened security site fencing at Crinnis and battered a viewing platform.
Angry residents have accused Commercial Estate Groups, the company behind the stalled regeneration project at Carlyon Bay, of causing an environmental hazard and shutting off the beach to prevent people seeing the destruction, potentially putting lives at risk.
Abby Crosby, marine conservation officer for Cornwall Wildlife Trust, said the charity had been alerted to the incident and is considering its next steps.
She said: "It's shocking. This poses a serious marine pollution incident," she said.
"It is worrying for marine life, particularly animals such as dolphins, porpoises and seals that could easily be caught up in the netting that's being dragged away and seems to have been washed up on Par beach."
Peter Price, 63, from campaign group Carlyon Bay Watch (CBW), said: "To some people this may seem pretty minor but the plastic netting could cause a considerable threat to marine life.
"The material is basically like giant plastic fishing nets washing around the sea and any number of marine creatures could become trapped."
Members of the group Friends of Par Beach have added that they are concerned about the material which was as "big as a room", when it washed onto the shore at Par last weekend.
CEG said it is investigating claims that the material, which washed up three miles along the coast, is from its site.
Anne Langley, 60, from Bodelva, branded the latest episode in the long saga as an unnecessary "environmental disaster".
She said if CEG had removed the foundations and the mesh following an enforcement notice issued by Cornwall Council they would not be experiencing "this plastic menace in the bay today".
"It has to be a danger to marine life, birds and shipping, as well as members of the public."
"Who is going to be responsible for the clean- up?"
CEG contractors have been on the site clearing the exposed plastic but will not restore the security panels until the storm abates.
Jacky Swain, site manager, said the beach is closed for the public's safety.
"We're urging the public to respect the closure, co- operate with the safety measures and not put themselves at risk," she added.
Cornwall Council said its contractors Cormac had visited Carlyon Bay last week and did not find the footpath blocked but that part of a claimed right of way, subject to a public inquiry in June, was restricted.
"We understand that members of the public who wish to gain access off the beach at this point will be allowed through the existing barrier by the owners," said the spokesman.