Facebook has rejected claims that private direct messages sent between users of the social network were appearing publicly on the recently-introduced timeline feature.
According to reports in France, private messages sent between 2007 and 2009 had started to appear in timelines, but Facebook said the rumours were false.
The social networking firm said investigations had revealed 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 said.
The company said that in 2007, the comments feature and like button did not exist and people tended to use wall posts to communicate instead of private messages, according to the Guardian.
Facebook said private messages and wall posts are treated differently and that no mechanism has ever been created that would allow a private message to be published on public timelines.
Engineers at the social networking firm said there was "no way" the two areas of data could get mixed up, according to the BBC.
Separately, the report said Facebook shares were under pressure after the US financial publication Barron's said the stock is worth only $15 a share – well below the $38-a-share flotation price.
On Wall Street, the shares ended on $20.79, down 9.1%, having fallen by more than 11% earlier in the day.
Barron's said: "Facebook's 40% plunge from its initial public offering price in May has millions of investors asking a single question: Is the stock a buy? The short answer is 'no'. What are the shares worth? Perhaps only $15."
Earlier this week, Facebook announced it is to suspend its facial recognition photo tagging service in Europe by 15 October, following a privacy audit by the Irish Data Protection Commission.
The technology, which suggests when registered users could be tagged in photographs uploaded to the site, was identified by regulators as one of the main privacy threats posed by Facebook.