Mounties in British Columbia say there's no evidence that the devastating fire that swept through the community of Lytton more than three years ago was arson.

Police have concluded their investigation into the June 2021 wildfire, saying they can't pinpoint the cause of the blaze that killed two people and wiped out much of the village and part of the First Nation, a day after a Canadian temperature record of 49.6 C was set in Lytton.

A statement from the RCMP says there is "no evidence to suggest the fire was intentionally set by the actions, or inactions, of any individual(s)" and the criminal investigation "has not determined the cause of the fire."

Police say they reviewed the weather conditions around the time, exhaustively searched two "areas of interest" where the fire may have started and interviewed 168 witnesses.

They say investigators collected evidence including 400 videos and photos and reviewed parallel investigations by the BC Coroners Service, BC Wildfire Service, and the Transportation Safety Board of Canada.

RCMP Chief Supt. Brad Haugli says in the statement that the focus of the investigation was on the how and why the fire started.

"While we have no single source or cause that can account for the devastating fire, it was not due to a lack of effort. Significant work was done to not only look at establishing and confirming what did happen, but to eliminate what didn’t happen," he said.

"We remain committed to the community and the important need to support all those impacted, while we also join in the collective efforts to rebuild."

Police say the findings have been shared with the Village of Lytton, the Lytton First Nation and the families of those who died.

They said the work investigating the Lytton fire will help the RCMP should it be required to investigate similar events in the future.