RCMP have charged two Alberta men with three counts of first-degree murder following a suspicious house fire in Castor.

Joshua Gregory Frank, 29, and Jason Klaus, 38, will also be facing arson charges after the remains of Gordon Klaus and his daughter Monica Klaus were found in the rubble of a burned-out farmhouse in Castor last December.

Sandra Klaus wasn't found but RCMP said that they believe she also died in the fire.

“We believe her remains were consumed in the fire,” Inspector Tony Hamori said.

According to police Jason was Gordon and Sandra’s son, Monica’s brother and the sole surviving member of the Klaus family.

Officials said the Calgary Medical Examiner’s Office could not determine the cause of death but they believe the deaths were homicide.

“We feel very strongly there was an element of planning and premeditation in this particular case,” Hamori told media Saturday.

Authorities also said a deceased dog located by police at the scene was found with a gunshot wound. 

Frank and Klaus will be in Red Deer Provincial Court on August 18.

With files from The Canadian Press