Police investigating a crash which killed three people last night have determined only two vehicles were involved in the incident, not three as first thought.

The crash happened about 7.50pm on the Tweed Valley Way at Stotts Island, near Tumbulgum, and involved a southbound silver Mitsubishi sedan and a northbound white Nissan Navara tray top utility.

A bicycle found at the crash site had been dislodged from the rear of the utility during the collision.

A 34-year-old woman from Murwillumbah, the driver of the sedan, died at the scene, as did the driver of the utility, a 27-year-old Yamba man.

The passenger of the utility, a 36-year-old man from the Clarence area, was ejected from the vehicle and also died at the scene.

Officers from the Ballina Crash Investigation Unit remained on site for several hours overnight, with the road reopening about 1am.

They are still working to determine the exact cause of the crash and would like to speak to anyone who observed either of the vehicles prior to the crash.

Anyone who can assist the crash investigators should phone Crime Stoppers on 1800 333 000.