A chief fire officer and his colleagues braved the hazardous remains of a devastated firework depot to protect the body of a fallen comrade.

An emotional Des Prichard, Chief Fire Officer for East Sussex Fire and Rescue Service, described how he and a small team of volunteers used abandoned cars for cover as they went back on to the Festival Firework site in Shortgate near Lewes.

The blaze on Sunday killed two firefighters and injured 12 people. Sussex Police have not ruled out the possibility of a criminal investigation.

Mr Prichard said he personally helped in securing the site where his colleague Geoff Wicker's body lay.

Despite a fear of further explosions, a small team of firefighters and police officers went back on to the site in the early hours of Sunday evening. By this time the body of the second victim, Brian Wembridge, had already been recovered.

Mr Prichard said: "This is not a faceless corporation. This is a team who support each other every day of their working lives and when we have a colleague who hasn't returned we owe that colleague a duty."

He added: "With a small team of volunteers we agreed risk assessing the scene. At the time it was our primary objective to recover our colleague. All the way to the scene our officers were at risk of explosions.

"There were a number of abandoned vehicles, police and fire engines, between the cordon and the scene which the team used as cover."

He explained that the recovery had been hampered by about 20 acetylene cylinders which investigators feared could explode under the heat.

He said: "The recovery of both of our personnel was a primary objective of the service so that we can support their families at this time of their need."

An investigation into the cause of the fire and explosions is under way with the Health and Safety Executive.

At a press conference yesterday Chief Superintendent Nick Wilkinson said a number of statements have already been obtained but stressed that the inquiry was still in its infancy.

He said: "We are seeking the truth. There is an investigation going on to look at all options. It's very, very early days. We have only just been able to get into the scene."

Mr Prichard promised an "open and honest" investigation. He said the inquiry would be long and protracted but he owed it to the families of victims Brian Wembridge and Geoff Wicker for the full facts to be found.

At the fire brigade's HQ in Eastbourne yesterday Mr Prichard and Ch Supt Nick Wilkinson appeared visibly shaken by the events of the past three days.

Mr Prichard said: "The loss of both Brian and Geoff is shared by all members of ESFRS but we feel for their families. Both are going through a tremendously difficult time at the moment.

"The investigation will ascertain where the officers were in regards to the explosion but it would be highly inappropriate to comment now. Both of those members of staff were working for ESFRS when they tragically lost their lives.

"There were a number, I believe, of acetylene cylinders in the building company adjacent to the site where the fire was. That will be flagged for the investigation."

An ESFRS spokeswoman said they could not say if the fire started from an electrical fault in the house as no one has been on site to determine anything yet.

Mr Prichard said Festival Fireworks was known to the brigade but licensed companies were classed as a lower risk because they already conformed to guidelines.

The drama began on Sunday shortly before 2pm when two explosions were heard and fireworks began shooting into the air.

The emergency services arrived soon afterwards but at about 2.30pm a third explosion occurred which, according to witnesses, was the loudest they had ever heard.

It is thought it was this blast which killed the two firemen who were dressed in full safety gear. The presence of acetylene cylinders and unexploded fireworks made the site extremely hazardous. A 200 metre exclusion zone was set up. No one was allowed access until yesterday afternoon.

Today, as investigators continued the painstaking task of sifting the scene for evidence, gas cylinders and some unexploded fireworks remained although the site has been assessed as safe for people to work in with extreme caution.

Ch Supt Wilkinson said: "Our actions are now to assess, search and document the scene forensically.

"This will be a meticulous and time consuming process."

Further details of the two firemen who perished also emerged at the news conference. Mr Wembridge, of Poundfield Road, Crowborough, was married with two sons. He had a "long and distinguished" career with the fire service, joining it as an operational firefighter in 1961.

He retired in 1994, completing his service as officer in charge at Lewes, before transferring to support services where his role included taking pictures at fire scenes. His images were seen in newspapers and on television, and he was well-known for his enthusiasm for the fire service, Mr Prichard said.

He added: "Brian's work is well regarded by many, many people and tributes for Brian have come from all areas of the service."

Mr Wicker, married with two daughters, joined the fire service more than 30 years ago as a retained duty system firefighter at Mayfield then Heathfield where he was watch commander.

In the mid-90s he joined the mobility and communication centre and was rapidly promoted to watch officer. Mr Prichard said: "Geoffrey was a warm and generous person and highly respected."

Twelve other people were injured in the explosion, including nine members of East Sussex Fire and Rescue Service, a Sussex Police sergeant and two members of the public.

A 39-year-old man from Uckfield, who was a passer-by at the time of the blast, last night remained in a serious but stable condition in hospital.