Bob Miller, 44, was killed as 70 firefighters dealt with the fire in the three-storey complex in the early hours of Thursday.

Mr Miller was one of the first firefighters into the building and it is believed he fell.

A police and fire service investigation has started into the cause of the fire and the circumstances of the death.

It is the most tragic thing that can happen in the fire service - when we lose one of our own

David Webb, chief fire officer

The fire comes as talks in London aimed at averting a national firefighters' strike enter their second day.

Union leaders have warned that next week's strikes over pay will go ahead if no agreement is reached.

Mr Miller had been in the service for 25 years and leaves wife Jane and two children aged 14 and 17.

He is the first firefighter to be killed in service in Leicestershire for 25 years.

The last firefighter to be killed on duty in the UK was Paul Metcalfe from the Greater Manchester service in 1999.

Firefighter deaths in the UK

1990: Six 1991: Four 1992: Three 1993: Four 1994: Two 1995: Five 1996: Three 1997: One

Chief fire officer David Webb, from Leicestershire Fire and Rescue, told BBC News Online: "We are absolutely devastated.

"It sounds a bit like a cliché, but it is like losing a family member.

"These people have been friends for many, many years.

"People can imagine how bad it is - from our perspective.

'Cause not clear'

"It is the most tragic thing that can happen in the fire service - when we lose one of our own. Thankfully it is very rare.

"He was one of the first men to go into the building and it appears he had some kind of accident.

David Webb: "We have lost a friend"

"At this time it is not clear why he fell and we do not know the exact cause of death."

The flag at Eastern Fire Station in Leicester, where Mr Miller was based, is at half mast on Thursday.

Fire Brigade Union secretary Andy Gilchrist said Thursday's talks between unions and employers would be overshadowed by the death.

Streets closed

"Naturally I'm saddened by the tragic death of the firefighter in Leicester and on behalf of the executive council send our sincere condolences to the friends and the family", he said.

The last firefighter to die on active duty was Paul Metcalfe from the Greater Manchester service in 1999.

Fourteen fire engines were sent to the scene

Thursday's fire, which started in the first and second floors of the building, was eventually brought under control at 0500 GMT.

Firefighters are still at the scene damping down.

Police have sealed off a number of side streets nearby.

Wimbledon Street, Morledge Street, Southampton Street and Midland Street are all closed.