A local campaign group claims news of a gas leak at the Dragon LNG site in Waterston is being "severely downplayed by authorities," with a tanker due to arrive at the terminal on Sunday.

The Health and Safety Executive (HSE) and Environment Agency Wales (EAW) confirmed that a gas leak had been detected at the Waterston site and an investigation was now underway.

"The site operator is taking all necessary measures to minimise risks to employees and the public while the investigation is being carried out," the statement said.

"The release is natural gas vapour and not liquid. Current estimates are that the release is not environmentally significant."

Gordon Main, a spokesman for the Safe Haven group said: "Residents are asking for an urgent meeting with both the HSE and engineers from Dragon LNG to explain the situation.

"Safe Haven has repeatedly raised concerns about siting these terminals so close to populated areas. The authorities and companies have always insisted that these concerns were unfounded because the tanks were so safe. Those claims look to have been severely shaken by this news."

Colin Orr Burns of Dragon LNG accused Safe Haven of "scaremongering".

He added the amount of gas involved was "absolutely minute" and posed "no threat."

"There is more methane produced by a herd of cattle standing in a field," he said.

He added: "I am concerned at the speculation and absence of fact and that it may cause alarm to people."