Gleision deaths: Families of miners in compensation bid
The families of four miners who died when 650,000 gallons of water rushed into their pit are seeking damages from the colliery's owners.
MNS Mining Ltd and pit manager Malcolm Fyfield were cleared of manslaughter.
Charles Breslin, 62, David Powell, 50, Philip Hill, 44, and Garry Jenkins, 39, died when water flooded Gleision mine in 2011 after a controlled explosion.
The Health and Safety Executive has been urged to release the results of its inquiry at the mine.
Thompsons Solicitors, which is representing the families, said the trial had reignited the call for the law to be made simpler and for owners and directors to be held more accountable.
"Getting a conviction on a charge of corporate manslaughter is very difficult as the prosecution has to prove the manager's actions amounted to gross negligence which is a hugely difficult legal burden," the firm said in a statement.
"It's too late now for the families we are representing but this is a wakeup call for those who talk about red tape and for this government, who with the Health and Safety Executive (HSE), have sought to dilute existing legislation there to protect mine workers.
"The fact is that the law in this area is likely to become weaker than it was when the disaster at Gleision occurred and, in memory of these men who went to work on the 15th of September 2011 and never came home, that cannot be right."
The solicitors echoed a call by Neath MP Peter Hain who said families "still need answers" and are asking the HSE to release the full report of its investigation into what happened at Gleision Colliery, near Pontardawe in the Swansea Valley, to the public.
The men were working underground with mine manager Mr Fyfield when water flooded the pit after they had blasted into old coal workings.
The prosecution claimed Mr Fyfield had been warned about the existence of the underground water, which later flooded the mine and said he thought he could breach the old central workings without causing any danger to the men.
But Mr Fyfield insisted he had inspected the area where the miners would work three times to ensure there were no dangers, including water.
Geologist Dr Alan Cobb said it was "possible" and "probable" that the water collected after Mr Fyfield inspected it.
Mr Fyfield also claimed shot-firer Mr Hill, who was killed in the tragedy, used multiple shots of explosives the day before, against his instructions.
Speaking for the first time after the trial, Mr Fyfield said the memory of his four colleagues was "the most important issue".