If it’s more formal, you don’t say anything. In almost all cases where someone would be tempted to lie, I should already know what the correct information is before I even asked a question.

In less formal situations, I would just keep asking follow-up questions. Lies are generally very shallow.

Edit: My point is that there are methods to call someone out without actually making direct accusations. Accusations are “hostile” and not generally worth derailing a meeting for something that can be dealt with later.