Two men and a woman were found dead Sunday near Oneida of the Thames First Nation, just southwest of London.
Officers were called to an area near Bodkin Road and Jones Drive around 10 a.m.
A source told CTV all three bodies were found inside a vehicle.
OPP are treating the deaths as suspicious.
They have released no further details about the identities of the three victims or how they died.
Chief Jessica Hill doesn’t believe those killed were from Oneida Nation. In a statement she said the incident “is a great concern for our Nation and demonstrates an issue for our community safety and the greater need for additional policing and/or security personnel within our territory.”
A post mortem examination has been scheduled Tuesday in Toronto.
OPP say they do not believe there is any threat to public safety.
Bodkin Road at Jones Drive remains closed while police continue their investigation.