It could take several months before its known what caused the suspicious death of a man and woman in southwest Edmonton last week.

Police say the autopsy performed on the man and woman has come up "inconclusive."

Toxicology tests are now being performed, but results could take up to several months.

On May 31, emergency crews were called to a home in the Riverbend area around 4 p.m.

Three people were rushed to hospital by ambulance.

Two people died of their injuries, while a third person, a woman in her 20s, survived and remains in hospital.

A close family friend told CTV News the two deceased were a married couple and that the woman in her 20s was the couple's daughter.

Police say the woman was in her mid-40s and the man was in his 50s.

Police have not confirmed whether this incident is a case of carbon monoxide poisoning.

Homicide detectives continue to investigate.