Ontario’s integrity watchdog is being asked to investigate the possibility that illegal lobbying may have played a role in convincing the governing Liberals to allow mixed martial arts in the province.

The New Democrats made the request Friday following reports that individuals are lobbying the Liberal government without registering — a violation of provincial laws.

Those reports suggest that former premier David Peterson may have lobbied the government on behalf of Ultimate Fighting Championship, the party said.

Peterson has denied he did any lobbying, but NDP justice critic Peter Kormos said Ontario’s integrity commissioner should investigate. In a letter to commissioner Lynn Morrison, Kormos urged her to find out whether illegal lobbying activities are taking place.