Police in Quebec say that when 188,000 households in southern Quebec were without power for two days last December, it wasn't due to bad weather or Hydro equipment malfunctioning.

Police are accusing Normand Dubé, a 53-year-old pilot, of intentionally damaging Hydro-Québec's high tension power lines.

Police say Dubé — a pilot and entrepreneur from Sainte-Anne-des-Plaines — allegedly threw objects on power lines in Mirabel, Wentworth and Brownsburg-Chatham to damage them.

Dubé appeared at the St-Jérôme courthouse Wednesday and pleaded not guilty to the 23 charges against him.

Hydro called police

The blackout, which began on Dec. 4 and continued Dec. 5, mainly affected the greater Montreal area, the Montérégie, the Laurentians, and the Outaouais regions.

At the time, Hydro-Québec spokesperson Serge Abergel told CBC News that the problem occurred when protection devices were tripped on two major transmission lines coming from James Bay. Abergel said Hydro did not know what caused the devices to trip.

Hydro later filed a complaint with police.

Major police probe

According to an extensive police investigation — carried out jointly by the Sûreté du Québec, the Saint-Jérôme police and the intermunicipal police force of Terrebonne — Dubé's suspected acts date back to 2009.

The investigation suggests that Dubé worked with a criminal group to allegedly commit criminal acts from 2009 to 2014 in the areas of St. Jérôme, Sainte-Anne-des-Plaines, Mirabel, Wentworth and Brownsburg-Chatham.

Police investigators looked into a legal case involving the city of Sainte-Anne-des-Plaines and Dubé. In that case, two city employees testified against Dubé.

Following their testimony, both employees suffered damages: one saw his house destroyed in a fire, while the other had a Molotov cocktail thrown in his basement early one morning.

During the police investigation that began in 2014, police confirmed that four suspects were arrested in connection with an arson in Sainte-Anne-des-Plaines — a fire that was at the residence of a city manager.

Since the beginning of the investigation, police have also seized a plane — an AC450 Aerocruise — worth $350,000.

Total of 7 arrests

Police arrested Dubé on Tuesday, along with six other men.

The charges they face include arson, conspiracy, death threats, harassment and vandalising objects worth more than $5,000.

Dubé is scheduled to return to court on June 9 for his bail hearing.

Crown prosecutor Steve Baribeau said he will object to Dubé's release because he believes Dubé poses a safety risk to the public.

"If he were released, the public's trust would be undermined," he said.