Another Edmonton police officer has been fired for disciplinary reasons, CBC News has learned.

In a hearing behind closed doors last week, Const. Adam Kube was terminated 16 months after he allegedly passed off an expired insurance card at a traffic stop while off-duty.

Officers had pulled over a motorcyclist on Oct. 22, 2011. The bike once belonged to Kube, but he had sold the bike two months earlier and cancelled the insurance.

During the stop Kube handed the officers an old pink card.

Last Tuesday, Kube was found guilty of corrupt practice and was immediately fired, CBC sources confirmed.

The hearing was closed to the public as Kube is facing a criminal trial on a charge of attempted obstruction of justice in the matter.

His mother, Janice Kube, told CBC News she is devastated.

"He loves being a police officer and he was good at it," she said. "We're very upset that this happened, and upset at the process."

She said the public needs to know why so many officers have been fired or resigned recently.

"This is our taxpayer dollars that are going down the drain instead of being used in other ways," she said.

Kube, who has been suspended without pay since last June, plans to appeal his dismissal, she said.

Kube is the fourth Edmonton police officer to be fired in recent months.

With files from CBC's Janice Johnston