A US lawsuit filed on behalf of LinkedIn Premium users accuses the social media platform of sharing their private messages with other companies to train artificial intelligence (AI) models.
It alleges that in August last year, the world's largest professional social networking website "quietly" introduced a privacy setting, automatically opting users in to a programme that allowed third parties to use their personal data to train AI.
It also accuses the Microsoft-owned company of concealing its actions a month later by changing its privacy policy to say user information could be disclosed for AI training purposes.
A LinkedIn spokesperson told BBC News that "these are false claims with no merit".
The filing also said LinkedIn changed its 'frequently asked questions' section to say that users could choose not to share data for AI purposes but that doing so would not affect training that had already taken place.
"LinkedIn's actions... indicate a pattern of attempting to cover its tracks," the lawsuit said.