Police say they detained Jeffrey Donald Furgala of Calgary on Saturday night in San Ignacio, 15 kilometres from the Guatemala border, for his own safety after he was unable to provide an address for where he resided.
The next morning, police say Furgala was found lying face up in his cell, unconscious, with blood in his nose.
Police say witnesses in other cells say they heard the sound of someone falling in Furgala's cell sometime around 1 a.m. Sunday, followed by loud snoring.
After police found him in his cell, Furgala was taken to a local hospital in critical condition on Sunday, before he was transported to Karl Heusner Memorial Hospital in Belize City for surgery.
San Ignacio issued a press release Thursday saying Furgala had died in hospital on Tuesday.
Local journalist Patrick E. Jones reported that Furgala never regained conciousness after being moved from the detention cell.
"There is a cloud of mystery surrounding the death off this Canadan," Jones said, adding that in the last year, seven people have died in police custody in Belize.
"That is what is fueling suspicions that something…probably happened from the time Mr. Furgala was taken into police custody and when he was found unconscious," he said.
Police Commissioner Allen Whylie said criminal and internal investigations have been launched into the death.
Chrystiane Roy, a spokesperson for the Department of Foreign Affairs, said Canadian officials are in contact with local authorities to gather additional information.