For years, critics of the Clintons have accused the dynastic political family of acting above the law.

Now, a secret 'gag' order put on investigators looking into presumptive Democratic presidential nominee Hillary Clinton adds credibility to those accusations — and it even has some FBI agents speculating about a possible conspiracy.

"The FBI has confirmed to a senior Republican senator that agents were sworn to secrecy — and subject to lie detector tests — in the Hillary Clinton email probe, an extensive measure one former agent said could have a 'chilling effect'," according to Fox News.

It's a highly unusual move that legal experts say undoubtedly sent a clear message to investigators. FBI agents are typically required to sign basic non-disclosure agreements as a part of their security clearance, but sources say that the "Case Briefing Acknowledgment" agents investigating Clinton were reportedly forced to sign is extremely unusual.

Such an order "comes from the very top and that there has to be a tight lid on the case." Additionally, the secret agreements can cause "group think" to take over, as agents are forced to hide details from colleagues and can only talk to a select few insiders, an anonymous source told Fox News.