The blast claimed the lives of three workers

The explosion at number five furnace at the site in Port Talbot in November 2001 - which also injured 12 workers - was the worst accident in the steel industry for 25 years.

On Tuesday, the Health and Safety Executive (HSE) published a new report which summarises its findings on the reasons for the accident.

The report says the explosion was so powerful it lifted the top half of the furnace up, which allowed approximately 200 tonnes of slag and molten metal and a large volume of hot blast gases to be ejected.

The blast furnace gas subsequently ignited and flames enveloped the furnace, it continues.

An initial report into the blast had revealed that approximately 48 hours prior to the incident there had been problems in the furnace caused by cooling water leaking into the furnace.

HSE Director for Wales Terry Rose said there was no evidence to suggest that anything other than water had caused the accident.

He met the bereaved families at Port Talbot police station on Monday night to tell them almost all evidence had been collected.

"The next stage will be starting to consider the legal position and the coroner's inquest," he said.

"it is important he (the coroner) establishes a cause of death and the verdict, whether accidental death or unlawful killing, may influence the way we look at the evidence and what charges we bring against the company or against individuals."

The explosion sent liquid iron hot coke and ash everywhere

HSE and the South Wales Police have been involved in a joint investigation into both the immediate and underlying causes of the incident, which Corus has admitted civil liabilty for.

The investigation has involved over 400 statements and the analysing of over 600 other documents, as well as input from a range of UK and international experts and scientists.

Mr Rose said the executive was keeping victims and their relatives up to date with its findings in the "difficult and complex investigation".

"Our sympathies remain with the families and we have kept them informed regularly on our progress," he said.

But Lee Jones, who spent weeks on a life support machine after the blast, said he was not being kept informed of the

"In the two years since it happened, I have never once spoken to a health and safety executive or a representative of health and safety," he said.

In January 2003, the blast furnace was reopened on the site of the explosion following a �75m reconstruction.

The rebuilding, which helped secure jobs at the site, was completed ahead of schedule against the backdrop of cutbacks and closures by the steel company.