Police are working to identify five men killed in an explosion inside an industrial unit which has been linked to the production of illegal alcohol.
The victims, believed to be eastern European, died after the blast in Boston, Lincolnshire, on Wednesday night, while a sixth suffered 75% burns.
On Thursday, investigators revealed they had discovered evidence that suggested the small industrial unit was being used as an illegal distillery when the explosion took place.
Lincolnshire Police Superintendent Keith Owen said: "What I can confirm is that we have found chemicals on the premises which tend to indicate either the manufacture or production of alcohol."
Police are awaiting the results of post-mortem examinations which were carried out on the bodies of the dead men and are still trying to identify them. The have also been unable to interview or identify the injured man, who underwent surgery at Queen Elizabeth Hospital, Birmingham.
Officers have urged anyone with any information or who may have missing relatives to contact them.
Mr Owen said the issue of illegal alcohol production was not a new one for the Boston area.
Earlier this year police, Trading Standards and Revenue and Customs swooped on six stores in the town, seizing counterfeit vodka. The spirit was later found to contain "Isopropyl" alcohol, widely used as a solvent and a cleaning fluid.
Last month Trading Standards bosses said Boston Borough Council's licensing committee had revoked the alcohol licence of one store, International Foods, and suspended that of another, Boston Deli, with action due to be taken against the other four.
Speaking at the time, Sergeant Jock Watt, from Lincolnshire Police's licensing team, said: "These decisions send out a clear signal that operating in this way will not be tolerated in Boston, or indeed across Lincolnshire. We hope that other premises who may have been tempted to sell smuggled or counterfeit goods from their venues will see this as a deterrent."