An outside law firm is looking into the accusations. (File)

The head of personal security for Mark Zuckerberg was on leave Friday pending a probe into complaints of sexual harassment and racism, some of it involving the Facebook chief's wife.

Allegations against Liam Booth, a former Secret Service agent now in charge of security for Zuckerberg, were made by two former employees who expressed complaints through a law firm, according to a contact for the Facebook co-founder's family.

"The family office takes complaints of workplace misconduct very seriously and our human resources team promptly investigates all such matters," spokesman Ben LaBolt said in response to an AFP inquiry.

"Mr Booth is on administrative leave pending the completion of this investigation."

An outside law firm is looking into the accusations, which include claims that Booth made homophobic, sexist and racist remarks involving other staff members and even Zuckerberg's wife, Priscilla Chan.

The accusations were first reported by Business Insider.