B.C.'s police watchdog has cleared Mounties of wrongdoing in a head-on crash that killed two drivers in Nanaimo last month.

The events leading up to the Jan. 14 crash began when a Nanaimo RCMP officer saw a GMC Sierra pickup truck "that aroused her suspicions," according to a report from the Independent Investigations Office.

The Mountie followed the truck as it drove toward the Island Highway and when she tried to pull it over, flashing the cruiser's police lights, the truck sped off.

The truck driver then reached the highway and turned the wrong way into a northbound lane.

"She switched off her emergency lights and radioed that the pick-up was 'trying to take off' and that she was going to 'let him go,'" the IIO report said.

The Mountie reportedly followed the vehicle south, but in a southbound lane, with her lights turned off.

The truck kept speeding along the highway and narrowly missed a head-on collision with a northbound vehicle, according to the report.

Seconds later, the truck collided head-on with another northbound vehicle, a compact SUV driven by 54-year-old trucker Cliff Bishop.

Bishop and the driver of the truck, 31-year-old Kurtis Timothy, both died at the scene.

Data from a recorder in Timothy's truck showed that just before impact, he was driving at a speed of over 170 kilometres an hour, the IIO said.

The police watchdog was called in to investigate the fatal crash as Mounties had given chase to the truck driver in the moments leading up to it.

After analyzing other data such as GPS, video footage and radio transmissions, the IIO concluded that the Mountie did not actively pursue the suspect by matching his high rate of speed.

It said that Timothy may have taken off when he saw police lights blaring behind him, but that the Mountie cannot be blamed for that if the traffic stop was authorized.

The RCMP officer has not given her account to IIO investigators, so the reason behind the attempted traffic stop is unknown.

The report concluded that no "improper or illegal act" on the officer's part was the cause of the fatal crash.