(Adds details on consumer complaints, background)
TORONTO, Sept 15 (Reuters) - Canada's privacy commissioner said on Friday that it has launched an investigation into the massive data breach at Equifax Inc after receiving complaints from Canadian consumers.
Equifax is still working to determine the number of Canadians affected by the incident, the Office of the Privacy Commissioner of Canada said in a statement.
The watchdog said it was not clear that only data from Canadians with U.S. dealings was exposed in the breach, contradicting what representatives at the company's Canadian call center had told some consumers.
An Equifax Canada spokesman did not immediately respond to requests for comment.
Canadians have taken to social media to complain of being ignored while Equifax offers free credit monitoring and a website where the 143 million U.S. consumers can check if their data was exposed in the cyber attack.
Equifax said earlier on Friday that it would likely need to contact fewer than 400,000 British consumers whose personal information may have been accessed in the breach.
The watchdog said Equifax has committed to notifying all impacted Canadians in writing as soon as possible. The company will also offer free credit monitoring to those individuals, it said. (Reporting by Alastair Sharp; Editing by Jim Finkle)