Facebook is investigating a report on the leak of an online personal database of over 267 million users.

According to a blog post on the Comparitech website, the database was available for download last week at an online hacker forum.

According to Comparitech, security expert Bob Dyachenko discovered a database that was publicly available and contained Facebook usernames, their IDs, and phone numbers. After reporting the discovery, the database was no longer available by Thursday.