The CRTC is investigating Rogers Communications because it believes the way the company deliberately slows down some of its internet traffic violates federal rules.

The probe stems from a complaint by the Canadian Gamers Organization, an advocacy group for people who play video games, that Rogers has been hindering online games.

Rogers admitted in March that its network systems were unintentionally slowing down, or “throttling,” internet traffic for the game World of Warcraft, then said it had resolved the problem.

It further acknowledged in September that other games and programs might be getting tripped up by its throttling. The Canadian Gamers Organization's complaint detailed slow internet speeds experienced while playing Call of Duty: Black Ops.

The CRTC informed the gamers group on Thursday that it has referred the matter to its enforcement division, meaning commission staff consider Rogers to be violating the Telecommunications Act or CRTC regulations. Those rules allow throttling of peer-to-peer file sharing programs like BitTorrent, but not of time-sensitive internet traffic like video chatting or gaming.

“We are aware of several games that have had issues, but we don’t know 100 per cent right now. We can’t tell from the ends of the network,” said Jason Koblovsky, a Canadian Gamers Organization co-founder. “But it’s quite clear the CRTC thinks there’s something wrong.”

The CRTC’s enforcement division has the power to inspect Rogers equipment or order a third-party audit of the company’s internet systems. That could help give a more comprehensive picture of whether Rogers is illegally throttling games, or if the Call of Duty slowdowns are just part of broader internet congestion.

“There’s a lot of confusion and testing that needs to be done,” Koblovsky said. “Sometimes it can takes months of troubleshooting at the consumer’s end to determine whether it’s throttling or not.”

Rogers spokesperson Carly Suppa said in an email Thursday night that the company has "just received" a letter from the CRTC and "we are reviewing its contents." She repeated the company's position that it believes it is complying with CRTC rules.

If the CRTC confirms Rogers is in violation, the regulator can go so far as to order the company to partially reimburse customers and to change its practices.

Many critics denounce internet traffic management because it amounts to censorship over what content gets priority transmission on the internet, violating the principle of "net neutrality."