OTTAWA -- A Facebook executive with ties to the ruling Liberals was grilled today about his preferential access to senior members of the Trudeau cabinet, even though no one from the social-media giant, including himself, is a registered lobbyist in Canada.

In his appearance before a parliamentary committee, Facebook Canada's public policy head Kevin Chan was questioned by New Democrat MP Charlie Angus on why he had yet to register as a lobbyist, given the fact he's met senior cabinet members, including Finance Minister Bill Morneau.

Chan, ex-policy director for former Liberal leader Michael Ignatieff, defended himself by saying it was unnecessary for him to register since the proportion of his lobbying activities falls short of the Lobbying Act's 20 per cent minimum threshold.

He also insists, for instance, that his meeting with Morneau strictly involved him showing the minister how to set up a Facebook Live event to broadcast a budget speech.

The testimony comes as policy-makers and regulators around the world examine how to better protect users' online data following a scandal that allegedly saw the personal information of 87 million Facebook users -- including more than 620,000 Canadians -- improperly accessed for political purposes.

Chan echoed Facebook CEO Mark Zuckerberg's acknowledgment this month that the company accepts responsibility for not doing enough to secure the platform and, despite recent changes, that more work needs to be done.

The committee also heard testimony Thursday from Facebook deputy chief privacy officer Robert Sherman, who estimated that just 272 people in Canada installed an app that enabled political consultancy firm Cambridge Analytica to access information from another 622,000 Canadians.

Under questioning by MPs, Sherman said by video link from California that it's possible users' private messages may have also been inappropriately accessed and that there may have been other data breaches involving Facebook data.