Canada's Competition Bureau has launched investigations into the parent companies of grocery chains Loblaws and Sobeys for alleged anti-competitive conduct, court documents reveal, with Sobeys' owner calling the inquiry "unlawful."

The Federal Court documents show the commissioner of competition launched the probes on March 1, saying there's reason to believe the firms' use of so-called property controls limits retail grocery competition.

The commissioner claims the controls that the grocery giants have baked into lease agreements are designed to restrict other potential tenants and their activities and are hampering competition in the grocery market.

The Competition Bureau revealed its investigation into the use of property controls in the grocery sector in February.