“We have no visibility into what they are doing with the computer and data systems,” one of the officials said. “That is creating great concern. There is no oversight. It creates real cybersecurity and hacking implications.”

A team including current and former employees of Musk assumed command of OPM on Jan. 20, the day Trump took office. They have moved sofa beds onto the fifth floor of the agency’s headquarters, which contains the director’s office and can only be accessed with a security badge or a security escort, one of the OPM employees said.

The sofa beds have been installed so the team can work around the clock, the employee said.

The new appointees in charge of OPM have moved the agency’s chief management officer, Katie Malague, out of her office and to a new office on a different floor, the officials said.