We are not desperately concerned about anything on board

Kevin Colcomb, Maritime and Coastguard Agency

Coastguards say there has been some very limited leaking of the cargo and a two mile exclusion zone has been set up around the vessel.

A French mine hunter has been sent to the area to survey the site of the wreck and is expected on scene on Wednesday morning.

Styrene is a known marine pollutant, and it is feared it could have a serious impact on sealife. The environmental group Greenpeace has warned of the potential for "a major disaster".

Fears played down

But the British Maritime and Coastguard Agency has played down fears the sinking could lead to an ecological catastrophe.

A British surveillance aircraft flew over the site on Tuesday afternoon and spotted some styrene in the water.

Scientists said the shiny, colourless substance appeared to be evaporating quickly while the bulk which remained in the ships tanks was likely to solidify within 40 days.

Kevin Colcomb, a senior scientist with the agency said: "In the short time we were flying over, it was visibly dissipating through evaporation.

"We are not desperately concerned about anything on board and have been told by fisheries experts that there may be only a localised effect.

"We don't like to see this happening, we don't enjoy marine pollutants going into the sea, but it has to be kept in context compared with other events."

Erika link

He said: "I could not agree with Greenpeace's view that this could lead to a major disaster."

Agency officials met French counterparts in Cherbourg on Tuesday night to discuss operational plans following the sinking.

Although the vessel foundered in UK waters, it was agreed that the French would maintain their operational lead in the counter pollution and salvage efforts with assistance and help from the British team.

The safety record of the tanker is being scrutinised by French authorities.

It has emerged that the same Italian classification firm that gave a clear bill of health to the Ievoli Sun and had also cleared the oil tanker Erika which caused an ecological disaster on France's Atlantic coast last year by spilling 10m tonnes of oil.