The Calgary Police Service says it did not know about an officer who was downloading child pornography until after he retired.

On Tuesday, police spoke to CTV News about the former officer's guilty plea in court.

Steve Huggett pleaded guilty on Monday to possession of child porn.

Court documents show Huggett admits he downloaded and viewed child pornography for up to four years and had done so while he was a police officer.

Police tell CTV News that Huggett never viewed the pornography on Calgary police computers. Officials say the computers are randomly audited by officials.

They also say the case is an isolated incident an all prospective members of the force undergo intensive interviews, a psychological test and a polygraph.

Huggett will be in court for sentencing on June 12th.