A family of three including a four-month old boy are among those to have died in the tragic accident at the corner of Canberra Avenue and the Monaro Highway.

NSW Police became involved in the pursuit of two people in a Mazda 626 in Queanbeyan just after 10pm last night.

The car, believed to have been speeding prior to the collision, careered into a Mazda 3 series vehicle turning right onto Canberra Avenue.

The impact of the collision broke the turning car into pieces. The couple, a 33-year-old man and 29-year-old woman, and the baby died at the scene.

Intensive care paramedics took the occupants of the Mazda 626, a 23-year-old man and 18-year-old woman to The Canberra Hospital. The man died a short time later. The female passenger was listed this morning in a critical condition.

ACT Policing Superintendent Mark Colbran said the NSW Police involved in the pursuit had terminated the chase shortly before the accident.

He said the officers involved were unharmed but had seen the accident.

A statement this morning from ACT Policing said the vehicle being pursued was confirmed as stolen.

"Initial investigations indicate the pursuit was initi ated after NSW Police attempted a routine traffic stop on the suspicious vehicle in Queanbeyan,’’ the statement said.

Several motorists traveling southbound on Canberra Avenue at the time of the collision stopped and tried to assist the five people injured. They have given statements to police and have been offered counselling.

The speed and circumstances of the pursuit will be investigated.

Police advised the intersection at Canberra Avenue and the Monaro Highway will be closed for some time.