A police officer who was driving at high-speed to attend a reported home invasion when he hit an unrelated vehicle, killing a mother-of-four on her way to church, has today been cleared of any wrongdoing.

The death of Liku Onesi, 47, who died when the 4WD Mitsubishi Pajero driven by her husband Ikenasio was turning into the Tongan Methodist Church in Flat Bush, Auckland, when it was struck by the police car, has been ruled a "tragic accident" by the police watchdog.

The Independent Police Conduct Authority (IPCA) concluded that the accident involved "unique circumstances that were not reasonably foreseeable" by the experienced officer, who was shift supervisor at Ormiston Road police station.

The officer had engaged in urgent duty driving down Ormiston Road on August 22 last year, which involved him driving at speed with the patrol car's red and blue flashing lights and siren activated.

The Onesis had turned across the busy road, heading for the church driveway, without seeing the police officer, who braked hard but could not avoid the collision.

Mrs Onesi's passenger side took the brunt of the impact, and she was flung from the vehicle. She died in the ambulance on the way to hospital.

The finding was one of two IPCA rulings out today involving police driving in Auckland last year.

In the other case, police driving at speed was also justified and deemed lawful in an incident that left two young men fleeing police on a motorbike with serious injuries.

Teenager Akshay Fenn was carrying a passenger on his motorcycle despite holding only a restricted bike licence when he fled police after being signalled to stop when recorded speeding and travelling in a bus lane in Mt Eden on July 28 last year.

He tried to evade police by weaving in and out of traffic and driving through a red light.

As the officer in pursuit of Mr Fenn turned a corner he saw the motorcycle, about 300 metres ahead, collide with another vehicle and both men were tossed from the bike.

Mr Fenn suffered several fractures to both legs while his passenger sustained a serious head injury. The driver of the other vehicle suffered minor injury.

"This was an accident caused by the actions of 17-year-old Mr Fenn that resulted in serious injury to himself and his passenger," said IPCA chair Judge Sir David Carruthers.

The Authority made no recommendations in either case.

"While in these instances the Authority has not found any breaches of police policy, the Authority is continuing its discussions with police about a review of policies connected with the pursuit of fleeing drivers," Sir David said.

"This is due to the conflict between the often prescriptive nature of the relevant polices and the reality of a fast-paced, time-pressured situation."

Counties Manukau Police today accepted the findings and extended "deepest sympathies" to the Onesi family.

"Police work hard to ensure the safety of our community and this is something we never want to see happen," said district commander Superintendent John Tims.

"Police are highly trained in urgent response driving and as stated in the report, the circumstances of the crash were not reasonably foreseeable by the officer involved. In a high pressure situation the officer acted as per his training and police policy dictated.

"That said, the outcome was an absolute tragedy and we have worked closely with the Onesi family to support them since the accident."

- APNZ