Facebook has strenuously denied reports that old private messages are popping up in users' timelines on the site.
The reports appear to have originated in France, where Facebook says it rolled out the Timeline feature, on Monday. Facebook representatives will be hauled up before the French data protection agency, the CNIL, later on Tuesday.
"Press reports have spread the word about a bug that caused messages from before 2009 to be posted on the Facebook accounts of French users," the French privacy watchdog said in a statement (in French). "CNIL will later today meet Facebook France officials to clarify the situation and the online posts."
However, according to the social network, the old messages people are seeing were wall posts, not private messages.
"A small number of users raised concerns after what they believed to be private messages appeared on their Timeline," Facebook said. "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."
A spokesman for the social network told ZDNet on Tuesday that Facebook had seen such reports before, in late 2011, and they were false then as well. He added that Facebook's systems treat private messages and wall posts very differently on a technical level, and it is simply not possible for one message type to bleed into the other's stream.
Facebook's spokesman also suggested that people used to carry out personal conversations on their walls through back-and-forth posts, particularly before comments and like buttons were introduced.
However, despite Facebook's denials, people continue to report seeing old private messages on their timelines.