MONTREAL -- The assumed leader of Quebec's anti-mask movement, Mario Roy, is facing criminal charges in connection with the blockage of the Louis-Hippolyte-Lafontaine tunnel after a protest against health measures back in March.

Roy and a group of anti-mask protesters allegedly blocked the northbound lanes of the tunnel, which connects the Montreal borough of Mercier–Hochelaga-Maisonneuve and the South Shore city of Longueuil.

An ensuing altercation with a motorist wielding a hammer was filmed and posted to social media.

Quebec's Crown prosecutors confirmed Roy appeared in court last Monday to face charges of conspiracy to commit an offence and mischief: the wilful obstruction, interruption or interference of the lawful use, enjoyment or operation of property whose value exceeds $5,000.

The 49-year-old is known to have ties to far-right and anti-immigration groups such as La Meute and Storm Alliance.

Roy's next court appearance is scheduled for June 29, along with his five co-accused; former La Meute leader Steeve Charland, his wife Karol Tardif, as well as Michel Jr. Deshaies, Tommy Rioux and André Desfossés.