It’s unknown how many users were affected, although a Facebook spokesperson said it had received a “small number” of complaints, including from British, US and European users.
According to reports, the site's members claimed private messages they had sent on the social network between 2007 and 2009 had been publicly displayed on their profile wall, in full view of their friends and family online.
However, the firm, which has been widely criticised in the past for continously breaching its users’ privacy, denies it was a breach, as the messages in question were old public PMs that existed before the social network’s strict privacy rules kicked in.
A Facebook spokesman said: "A small number of users raised concerns after what they mistakenly believed to be private messages appeared on their Timeline.
"Our engineers investigated these reports and found that the messages were older wall posts that had always been visible on the users’ profile pages. Facebook is satisfied that there has been no breach of user privacy."