Superintendent of Police of South 24 Parganas district, Sunil Chowdhury, said the man, a relative of policeman on duty, was injured as his hands were burnt in the fire.
He was admitted to a hospital here.
Four fire tenders controlled the fire in half an hour, he said, adding everything kept inside the tent, which was located beside the police control room, was destroyed.
The reason behind the fire was yet to be ascertained.