Police and fire investigators have not yet determined what led to an explosion and fire that destroyed a house last month in Corner Brook. (Courtesy of Bram Russell)

The Royal Newfoundland Constabulary says investigators have determined that vapours led to a stunning explosion and fire that levelled a house in Corner Brook last month.

The house on Quigley Place was destroyed by fire on March 29.

The owner was travelling at the time of the fire. Her neighbours heard a loud explosion during the evening, and saw a fireball erupt in the home.

The RNC said an investigation that also involved the Corner Brook fire department determined that a flammable vapour caused the explosion, which in turn led to the fire.

However, investigators don't know what type of vapour it was, or where it originated.

Police said the investigation is still underway, and that the police are looking for assistance from anyone who may know something about the incident.