Fresh calls have been made for a full inquest into the Gleision mining disaster that claimed the lives of four workers killed when the tunnel in which they were working filled with water in 2011.

The demand is being made following fresh claims that the disaster was the result of  illegal operators who failed to record their workings on the mine plans.

On September 15, 2011, seven miners were working with explosives in a narrow coal seam in the mine two miles east of Pontardawe.

Following a blasting operation into a separate disused flooded network which was intended to increase air circulation, the tunnel in which the miners were working filled with water.

Three miners escaped however the remaining four became trapped underground.

A search and rescue operation was instigated however the bodies of four men were discovered the following day.

They were named as Charles Breslin, David Powell, Philip Hill and Gary Jenkins.

Following investigations into the disaster, manslaughter charges were brought against both the site manager and MNS Mining Ltd, however both were found not guilty.

Now, South Wales West MP Sioned Williams has backed calls for a full inquest.

“Valid and important questions are now being raised into what led up to, and what happened at the Gleision Colliery, and these questions need to be considered in order to understand whether this was a preventable tragedy,” said Sioned Williams.

“The families and the wider community as a whole all deserve answers to these questions, having suffered such a terrible loss.

"A full inquest is needed in order to finally bring closure to the families of the victims, all those linked to the mine, and to the whole community.”

The calls were presented yesterday  (Thursday 21 April) in a letter to the Coroner’s office for Swansea and Neath Port Talbot, from the families, mine owners and community representatives.

The request is being made after new questions emerged in a report by a leading coal industry expert who claims that years of alleged failure by the regulatory bodies (HSE and Coal Authority) to enforce the regulations may have resulted in operators illegally working coal and not recording it on the mine plans.

A full public inquest was originally opened and adjourned in 2013.