The Winnipeg Police Service has launched an internal investigation into its K-9 unit.

Sources tell CTV it came after a WPS bomb dog remained in service at the Winnipeg airport without proper validation.

The Winnipeg Police Association confirmed that an investigation is underway, but said it was not provided with details.

“It’s looking into some practices that were being conducted in the canine unit,” said WPA president, Moe Sabourin.

Sabourin said the officers within the unit are still in active duty.

The Winnipeg Police Service said in a statement:

"This is a private personnel matter therefore the WPS will not be providing a comment."

The Winnipeg Airport Authority said it was left in the dark about the allegations.

Breanne Talbot, manager of communications for WAA, said that the WPS has not told the WAA about the case or internal investigation.

She said the WAA hires a third party, like the WPS or RCMP, to perform security and relies on that contractor to make sure dogs are properly certified.

She said the WPS has not told the WAA about potential contract breaches in relation to the allegations, but said the WAA would work with police if any were found in their internal investigation.

George Leonard, a master dog trainer, said training standards for explosive dogs are rigorous.

He said typically dogs are tested yearly. The test takes three days and is performed by a third party.

Leonard said that explosive dogs require extensive logs that detail the time and nature of their training and certification.

He said that the lives of the dog, handler and other people can depend on proper training.