NZME. News Service understands that the police were acting on information that the 32-year old female passenger had allegedly smuggled drugs through Christchurch International Airport.
Sources say police saw the woman being picked up at the airport by the silver BMW.
Officers tailing the car began a pursuit at about 4.45pm after it allegedly backed into another vehicle at the junction of Wairakei Rd and Johns Rd, just outside the airport.
The vehicle was driven away from police before it rammed through an armed police roadblock on Yaldhurst Road and collided head-on with another car, causing injuries to the occupants.
Superintendent Gary Knowles said the 32-year-old female passenger in the BMW was under police guard in Christchurch Hospital under the Misuse of Drugs Amendment Act.
Graham Theo Payne, 55, the driver of the BMW, appeared in Christchurch District Court today facing one charge of failing to stop when followed by police under lights and three charges of reckless driving causing injury.
Inquiries were continuing into the second passenger, a 40 year-old man.
Police said the 79-year-old man who was driving the other car is reported to be in a stable condition.
The front seat passenger, an 80-year-old woman, was in a critical but stable condition.
The other passenger, a 70 year-old woman, was in a serious but stable condition.
Canterbury Police crime services manager Detective Inspector Virginia Le Bas is overseeing the police investigation.
Mr Knowles said: "The pursuit and crash has been referred to the Independent Police Conduct Authority and a senior investigator from outside Canterbury District will have oversight of an internal investigation into police, practices and procedure.
