AN investigation is continuing to discover what caused a 200ft high steel chimney to erupt into a fireball, killing two steeplejacks.

Detectives, forensic scientists and a Heath and Safety Executive investigation team are expected to remain at the Carnaud Metalbox Food UK plant in Chew Moor Lane throughout the day.

The two steeplejacks, aged 23 and 41, were killed when they were engulfed in a fireball as they worked to dismantle the tower on a cradle inside.

It is thought a spark ignited flammable chemicals coating the inside of the tower at the site in Westhoughton on Thursday evening.

Both men, who have still not been named by police, were employed by Churchill Steeplejacks, based at Ruddington in Nottingham.

Company spokesman Wayne Murray said yesterday their deaths have shocked the family-run business.

He said they had both worked for the business for a number of years.

Mr Murray added: "It is just tragic. This is a family-run business and it is like we have lost a brother. They were not just workers. They were like family.

"In our line of work there is always a certain amount of risk and what has happened here is a freak accident."

Mr Murray said one of the men was one of the most experienced steeplejacks in the country, adding: "There is no certificate or qualification in this country that he did not possess."

The victims' families have been informed.

Greater Manchester Police confirmed that an initial multi-agency investigation had been launched to see why the two men died.

The police will be working with the fire service, Health and Safety Executive and the Forensic Science Service on the investigation which is likely to continue into next week.

A spokesman from GMP said: "At this stage we will not be disclosing the identities of the men who have died as formal identification has not yet taken place."