In response to the email revelations the councillor responsible for the environment has stressed that testing must be done so that a conclusion over the health implications can be put to rest.

Councillor Aaron Watkins had faced accusations that he misled the public by telling the council in November that “tests were carried out by the environment agency” and those results show it “does not pose a direct risk to health”.

His claims were rejected by the Environment Agency and Public Health England, with the Environment Agency claiming in February that it had not carried out any tests and Public Health England denying they had been involved.

However, the emails show that the comments made by Mr Watkins were in line with the advice given by Public Health England at the time, despite them later admitting uncertainty over the claim.

Mr Watkins said: “I had been clear in my statement based on the information I had received at the time. We have setup a steering group so that we can understand what tests the Environment Agency has done and to gauge an understanding of what advice Public Health England wants to pass on.

“The council’s focus has continued to be on getting the tests done and we are still striving to get this done.

“We are making progress and we are working with Environment Agency to work toward testing.

“It is also not just about the testing, but about the Environment Agency having responsibility and following up and making sure plans are in place and correct procedures are in place with companies on the docks.

“Testing is the most important though to be sure that there is no direct risk to health, which is what Public Health England have said but they don’t seem to have any evidence to back that up.”

Councillor John Allen, ward councillor for Tilbury St Chads, said: “There is not enough being done. I have called on the authorities to do tests and I understand no tests have been undertaken to determine whether it is harmful to the public’s health.

“We don’t know whether it’s detrimental and I would call on the authorities to do the testing which I understand is quite expensive but needs to be done, then we can look into where it is coming from.

“I certainly believe that the people of Tilbury are owed at least these tests to be undertaken. All we know right now is that it is a metallic structure because it’s attracted to magnet.”

He added: “The advice being given is not correct because no one has looked into it properly. I still think residents are being misled and it raises the question of does big business come before the public’s health?”