Detectives are investigating whether an Easter Sunday crash, which killed a husband and wife, was a deliberate act by the driver.
Preliminary information indicates the vehicle was travelling southbound along David Low Way at around 7am, when it left the road and hit a tree at Pacific Paradise.
Detective Senior Sergeant Daren Edwards said a suicide note was found in the vehicle and another located at a residence.
Police are appealing for anyone who witnessed the crash to contact them.
Police would also like to speak to anyone who saw the vehicle, a 2016 white Nissan Qashqai SUV, driving in the area prior to the crash, as well as any motorists with relevant dashcam footage.
The two occupants, a 69-year-old male driver and 68-year-old female passenger were trapped for a period of time before being extricated and transported to Sunshine Coast University Hospital, where they both died.
For assistance please call Lifeline on 13 11 14 (24 hour counselling, information and referrals) or the Beyond Blue Support Service 1300 22 4636.