Penn State spokeswoman Lisa Powers also disclosed that the Harrisburg-based U.S. attorney's office requested "reporting requirements of employers and staff relating to allegations of misconduct by staff or individuals associated with the university."
The new details were released a day after the Feb. 2 subpoena was first confirmed by the university. Powers said Penn State is fully cooperating with the request.
Heidi Havens, a spokeswoman for U.S. Attorney Peter J. Smith, declined to comment Friday on the subpoena.
Powers also revealed Friday that the request for "certain information" goes back to 1998, the year university police investigated a mother's complaint that Sandusky, then the football team's defensive coordinator, had showered with her 11-year-old son in a school locker room.
Sandusky, 68, is confined to his State College home as he awaits trial on 52 sex abuse charges. He denies the allegations.
Along with Sandusky and the university, the subpoena also sought information about athletic director Tim Curley, retired vice president Gary Schultz and former president Graham Spanier.
Spanier has not been charged with any crime.
Curley and Schultz await trial in Harrisburg on charges that they lied to a grand jury investigating Sandusky and failed to properly report suspected child abuse after a football team assistant told them of a 2002 incident involving Sandusky and a boy inside the team's showers. Curley and Schultz are free on bail. They are seeking dismissal of the charges.
Powers said the subpoena asked for "reporting requirements of employers and staff relating to allegations of misconduct by staff or individuals associated with the university."