Hong Kong’s privacy watchdog is seeking answers from Facebook on what it is doing to protect user information in the wake of a global data harvesting scandal, and how much its 5 million active users in the city have been affected.

Speaking exclusively to the Post on Wednesday, Privacy Commissioner Stephen Wong Kai-yi said the social media giant would have to identify any loopholes, and failure to plug them would warrant legal action by his office.

This adds pressure to Facebook, which has lost tens of billions of dollars in market value after Cambridge Analytica, a British data firm with ties to US President Donald Trump’s 2016 election campaign, was accused of illegally harvesting information from around 50 million users without their knowledge.

Wong, also a barrister by trade, said public concerns sparked by the scandal had prompted his office to step in and demand answers from Facebook, although no formal complaints had been received yet.

While Facebook had an operational office but not a data server in Hong Kong, Wong said, his intervention was justified, given its 5 million active accounts in the city.

“If they have some control over users’ data, and some of that data comes through Hong Kong, then even if Facebook does not have a server here, it would still count as information gathering in Hong Kong,” Wong said. “If we don’t chase after them as a matter of public concern, who else has the power to do so?”

The privacy chief said it would primarily be a “fact-finding” mission to understand Facebook’s operations and data protection policies in the city, stressing that his office did not have any preconceived notions about the company.

His office would closely follow investigations launched by United States and British authorities, as well as similar inquiries made by other privacy commissioners around the world.

“Due to widespread concern and the vast number of local user accounts, we hope to speed up our inquiry and hopefully complete it within one to two months,” he said.

Wong would not rule out probes into other major technology companies’ handling of personal data in the city, if necessary.

In a written reply to the Post, Facebook said: “We’ve been in regular dialogue with the Privacy Commissioner’s Office on this matter and will continue to address any feedback and advice from the commissioner.”

Facebook on Wednesday also globally announced a redesign of its privacy settings, offering step-by-step guides for users to access and even delete their personal data.

Lawmakers have also called on the privacy watchdog to investigate Facebook locally and issue guidelines to marketers regarding the protection of personal data.

In a letter to the commissioner, information technology sector lawmaker Charles Mok urged him to press Facebook on whether Hong Kong users’ information had been transferred to any third party by any means.

Echoing concerns about the suspected use of private data to influence US elections and Britain’s Brexit referendum, Mok also urged the commissioner to investigate similar abuse, if any, in local polls.