Federal investigators have sought more records related to three employees in the city's Department of Code Enforcement.
The city received a subpoena from the U.S. Attorney's Office in Buffalo on Friday seeking the employment files for former Buildings Commissioner Guy A. Bax, as well as inspectors George Amendola and Peter Butry.
The subpoena also seeks the "roster record" of each employee, as well as "employee acknowledgement forms" signed by the three that "should include but not be limited to the signed acknowledgement of receipt and review of the Niagara Falls ethics policy," according to the subpoena.
The city has until Jan. 12 to provide the records.
Bax has been on paid administrative leave since agents from the FBI and Internal Revenue Service seized City Hall documents in July 2009 from what was then known as the Department of Inspections. It is now known as the Department of Code Enforcement.
He also has been stripped of the buildings commissioner title, and was replaced by Dennis Virtuoso when he was placed on paid leave.
Amendola and Butry, who also were placed on paid administrative leave, returned to work in February under an agreement in which they serve with "expanded oversight" of their activities, Mayor Paul A. Dyster said.
The three employees were named in a search warrant application in July 2009 connected to a federal investigation of plumbing contractor John J. Gross Jr. Investigators at the time searched several locations, including City Hall and the offices of Gross' plumbing company, in a wide-ranging probe into Gross' activities.
No charges have been filed in the investigation.
The three employees were placed on paid leave shortly after the search.
Court documents issued then said investigators had "probable cause to believe that the Gross Organization has corrupt relationships with members of the Niagara Falls Department of Building Inspections."