A man has suffered critical head injuries after he was pushed by police in far north Queensland.

Police say the 52-year-old man approached officers aggressively as they arrested a woman for throwing a bottle of alcohol in their direction at Normanton on Thursday night.

It is alleged he fell backwards and hit his head on the road after police pushed him away in an attempt to avoid personal injury.

Officers immediately provided first aid and called paramedics, police say.

The man was taken to Normanton Hospital before being transferred to Townsville, where he remains in a stable but critical condition.

Officers from the Ethical Standards Command will investigate the injury in custody and the Crime and Corruption Commission has been notified.