Police in Quebec secretly tracked phone calls received and made by at least six French-language reporters in 2013, the broadcaster Radio-Canada has reported, widening a media surveillance scandal that had already sparked furore in the Canadian province.

Quebec’s provincial police force, the Sûreté du Québec, obtained warrants to track the journalists’ calls but did not register their conversations, the public broadcaster reported on Wednesday.

The police force did not immediately respond to a request for comment on the story.

Provincial and municipal police were tracking the calls to find the sources of leaks to media, including one case involving an officer implicated in a probe into allegations that cops had been fabricating evidence, Canadian media said.

Radio-Canada named three of its own journalists – Marie-Maude Denis, Isabelle Richer and Alain Gravel – as among those affected.

Denis tweeted: “I just learned that my incoming and outgoing calls have been spied on by the Sûreté du Québec in 2013.”

Je viens d'apprendre que mes appels entrant et sortant ont été espionnés par la Sûreté du Québec en 2013. — Marie-Maude Denis (@mmdenisrc) November 2, 2016

Quebec’s premier pledged on Tuesday to reform legislation to better protect press freedom in the mostly French-language province, following reports that Montreal police were spying on Patrick Lagacé, a popular columnist at newspaper La Presse by tracking his cellphone calls, texts and whereabouts.

Legislation to be introduced by the provincial government would make it harder for police to obtain a search warrant against journalists, local media reported.