Adds Canadian lawmaker's statement in paragraphs 5-6, context in 8-9

By Ryan Patrick Jones

TORONTO, Feb 27 (Reuters) - Canada's privacy watchdog has opened an investigation into X, the social media platform owned by billionaire tech mogul Elon Musk, on whether its use of Canadians' personal data to train artificial intelligence $(AI)$ models broke privacy rules.

The Office of the Privacy Commissioner of Canada said in a statement on Thursday that it launched the probe after receiving a complaint.

"The investigation will focus on the platform's compliance with federal privacy law with respect to its collection, use, and disclosure of Canadians' personal information to train artificial intelligence models," the statement said.

The office did not provide any additional details about the nature of the complaint.

An opposition New Democratic Party lawmaker, Brian Masse, said he had written to the privacy commissioner this week calling for an investigation into X.

"I'm pleased to see the privacy commissioner agree to launch an investigation into X's use of Canadians' data," Masse said in a statement. "Transparency and sunlight are crucial at a time when algorithms could be manipulated to spread misinformation," he added.

X did not immediately respond to a Reuters request for comment.

The investigation into X comes at a time of increased tension between Canada and the United States over trade, border security and a digital services tax on U.S. technology firms.

President Donald Trump, who has tasked Musk with downsizing the U.S. government, vowed earlier on Thursday to follow through on proposed 25% tariffs on Canadian and Mexican goods from March 4 because deadly drugs were still pouring into the U.S. from those countries.

Musk, CEO of electric vehicle maker Tesla TSLA.O, is also the founder of artificial intelligence startup xAI.

Following Musk's 2022 purchase of Twitter and its subsequent renaming as X, the social media platform made xAI's Grok chatbot available to its users.

Grok is an AI assistant that helps users complete tasks, including answering questions, solving problems and brainstorming, X says on its website.

Last week, xAI introduced Grok-3, the latest iteration of its chatbot, which is being rolled out immediately to Premium+ subscribers on X.

Generative AI models such as Grok require lots of data to train and develop.

Canada's privacy legislation set out rules for how private-sector organizations can collect, use, and disclose personal information in the course of business, the privacy commissioner has said on its website. They include rules around consent, disclosure, retention and safeguards.

(Reporting by Ryan Patrick Jones in Toronto and Additional reporting by Ismail Shakil in Ottawa; Editing by Muralikumar Anantharaman and Jacqueline Wong)

((ryan.jones@thomsonreuters.com;))