Man fights for life after Qld police chase

An investigation is underway into an alleged 70 kilometre police chase through Queensland's Darling Downs that ended with a driver critically injured after he hit a tree and had to be cut from his car.

Queensland Police deny Monday night's incident was a "pursuit", instead saying officers tailed the car at a considerable distance before a failed attempt at using road tyre spikes to stop it.

Police first spotted the car driving dangerously on the Warrego Highway at Dinmore near Ipswich at around 8.20pm.

They then followed the vehicle until it ploughed into a tree east of Helidon twenty minutes later.

The driver had to be cut free from the wreckage and remains in a critical condition in hospital.

The Forensic Crash Unit and Ethical Standards Command are investigating.