It was a three-year child pornography investigation by both Canadian and international police agencies that resulted in hundreds of people arrested and charged including an Edmonton man.

On Thursday, officials with the Alberta Law Enforcement Response Team (ALERT) Internet Child Exploitation (ICE) team said that Andrew Liu, 66, from Edmonton, is facing a charge of child pornography.

“Members of the Northern Alberta ICE Unit executed a search warrant with the assistance of the Edmonton Police Service at his residence in downtown Edmonton,” Sgt. Mike Lokken with ALERT said. “As a result of that, we have charged him with possession of child pornography.”

Investigators searched Liu’s apartment in October, and seized some items.

Documents filed with the Alberta Law Courts stated Liu is accused of possessing child porn, dating back to May 2007.

CTV News has learned that Liu worked for the last three decades as a mathematics professor at the University of Alberta.

U of A officials declined a request for an interview, but a spokesperson told CTV News Liu has retired as a full time professor, and was on a part time teaching contract – although he is not currently teaching, and it wasn’t clear when he taught his last class.

Liu is one of three Alberta men arrested and charged in the massive sting, two Calgary men: Jonathon Robert Gerbrandt, 34, and Kevin Michael Owad, 39, are facing two and three child pornography-related charges, respectively.

The arrests were made as part of a massive investigation called ‘Project Spade’ initiated by the Toronto Police service.

The massive child exploitation investigation started on October 20, 2010 – beginning with investigation into a Toronto man, who allegedly operated a child exploitation movie production and distribution company, then shared those videos around the world.

Investigators said the images were recorded in Romania and Ukraine.

Toronto police said their investigation uncovered about 45 terabytes of data – which one official said is equivalent to a stack of paper as tall as 1,500 CN Towers.

Officials said the effort has ended with 341 people charged, globally.

ALERT said 38 international police agencies from around the world were involved in the investigation, and 386 children ended up being rescued from child exploitation.

Police said the alleged victims are between the ages of 5 and 12-years-old.

Liu has been released on bail, and is awaiting his next court appearance in December.

With files from Laura Tupper and Susan Amerongen