The social media company copied the email contacts of new users as part of the process to set up and verify their Facebook account, according to Business Insider, which first reported the news.

A Facebook spokesperson told Business Insider: “When we looked into the steps people were going through to verify their accounts we found that in some cases people’s email contacts were also unintentionally uploaded to Facebook when they created their account. We estimate that up to 1.5 million people’s email contacts may have been uploaded.”

Data was not shared with anyone and is being deleted, Facebook said.

It is the latest in a run of privacy oversights from the company, whose data practices have been under scrutiny since the Cambridge Analytica revelations in early 2018. Last month, it said it had resolved a glitch in its internal systems that left millions of user passwords exposed to its employees.

Chief executive Mark Zuckerberg recently outlined his plans to shift to a "privacy-focused platform" as the company looks to focus more on building its private messaging offer.