The Washington Post cited two government officials as saying on Tuesday the FBI contacted a technology firm that helped manage Clinton’s private servers to inspect their level of security.
It also found the FBI contacting Clinton’s lawyer with questions about the security of a thumb drive in his possession that contains copies of emails the former state secretary had sent during her tenure.
The investigation, which does not implicate Clinton directly, comes after the US State Department Inspector General raised concerns in July that at least four emails stored in Clinton’s private account may have contained sensitive or classified information.
The Democratic Party frontrunner in the 2016 presidential election denied sending or receiving anything marked classified at her private email address.
Meanwhile, another Washington-based media cited Clinton’s then-chief of staff as saying her private email server may have malfunctioned in late 2012.
