Hazardous materials have been stored illegally at a Kent firm, it has been revealed.

Medway council today confirmed Arcelor Mittal, based at Chatham Docks, has brought potentially explosive material ammonium nitrate onto the site without the statutory permission.

The authority has now launched an immediate investigation.

The shock news comes after Arcelor Mittal applied for permission to store 2,500 tonnes of the potentially explosive material at the site.

But it has now been confirmed the firm has already brought the substance into the docks without the proper permission. It is not known how much is being stored there.

The finding was made after Liberal Democrat councillors questioned Medway Council about the possibility that the chemicals were already on site.

A spokesman for Medway Council said: “Following enquiries made to the company’s agent, Medway Council discovered on Thursday that this substance has already been brought into the docks without the statutory permission. The council was not previously aware that this was the case.

“The council immediately alerted all the agencies consulted on the original hazardous substances licence application and urged them to give this matter their most urgent attention.”

Andy Stamp, deputy leader of Medway council's Lib Dems said the group was appalled at the news.

He added: "It's going to make residents even more worried.

"We were accused of scaremongering earlier on in the week but we have now been proved right that we have to remain on the side of caution.

"There now needs to be a full open debate and inquiry into what has happened and why it has happened."

Medway Council is now investigating. Arcelor Mittal could face legal action. A spokesman for the company was unavailable to comment.