Andrew Hutin: One of three victims

For the last 10 weeks temperatures inside furnace have remained well over 1000 degrees celsius making it impossible for investigators to enter.

However, now the temperature has cooled sufficiently for a remotely-operated camera to enter the site on Wednesday.

If it is found to be safe, investigators from the Health and Safety Executive and South Wales Police may enter the furnace next week.

First Minister Rhodri Morgan told the Welsh Assembly on Tuesday that police investigators had now been to the site of the furnace.

Rugby player Andrew Hutin, 20, Stephen Galsworthy, 25, and Len Radford, 53, died in the explosion.

Five workers are still receiving treatment in Morriston Hospital in Swansea and Mr Morgan said they were making a "miraculous recovery".

Mr Morgan is to meet Corus Chief Executive Tony Pedder later this month to discuss the future of iron supply at the south Wales plant.

Rhodri Morgan has praised the workers 'miraculous recovery'

The police investigation into what happened is being headed by chief investigating officer, Detective Chief Inspector Ken Isaac.

The Health and Safety Executive led by Brian Drinkall, is working alongside police to establish the cause of the incident.

Their joint inquiry is being carried out in three main stages.

First is the evidence from the steelworkers themselves, including the men who were working in the furnace and who survived against the odds.

Cooling process

Second is the evidence from the computer records and data from the furnace control room.

Then there is the physical examination of furnace number five itself into which Corus sprayed a 1000 tonnes of cold water in last month to aid the cooling process.

Corus has already moved to head off criticism that the blast may have been caused by a fault in the furnace which was due for a partial refit under refurbishment plans.

In December 2001 A spokesman said it would be "premature to assume that prior to the explosion there was a defect".