"The person in the car was wanted for an unrelated serious crime. He started driving at high speed through roads like Te Irirangi Drive and around the Flat Bush area," he said.
"During this time, Eagle was following. We didn't have any police cars pursuing him directly. After a while, he entered the motorway going the wrong way at Highbrook.
"He crashed into a member of the public's car about 100m onto the motorway."
Police are yet to say whether any charges will be laid.
Klussein said two people - the two drivers - suffered serious but non-life threatening injuries.
Another two people in a third vehicle that got caught up in the crash suffered minor injuries.
Police earlier confirmed that the vehicle seen travelling down the wrong way of the Highbrook Drive off-ramp had been stolen.
Authorities were forced to close off the motorway from Princes St for just over two hours as emergency crews attended the scene.
An AA spokeswoman said traffic built rapidly after the creash with the trip from the city to Manukau taking almost two hours at 11am compared to the 15 minutes it would usually take at that time.
Traffic was back to normal once all four lanes were re-opened just before 12.30pm.
The impact wasn't restricted to southbound journeys with people travelling northbound on the Southern Motorway also experiencing delays. The trip from Manukau to the city taook about twice as long as usual by mid-morning - about 30 minutes, compared with the normal 15.
