A 33-year-old man and a dog died in a caravan fire in Holbeach Fen on Sunday morning.
Police and fire officers are trying to establish the cause of the incident at Heron’s Cottage caravan and camping site in Frostley Gate.
Police said on Monday: “This fire was reported to us at 10.14am yesterday, by the Fire and Rescue Service who were attending the fire.
“A body was found within the caravan. A dog also died.
“We believe that the deceased is 33-year-old local man who recently moved into the caravan. We are working to confirm his identify and to inform family and friends.”
The spokesman added: “We are treating the cause of the fire as unexplained and are working with the Fire and Rescue Service to establish what happened.
“Anyone who has any information about the incident is asked to call the 101 non-emergency number and quote incident number 126 of 13th March 2016.”
A postmortem examination is due to be conducted today (Monday).
Firefighters were called at 9.45am, with crews from Long Sutton, Spalding and Boston attending.