"The inspector general should immediately broaden its investigation to include Hines VA and to deliver a swift and immediate report," Kirk said, noting that there was a link between the facilities in Arizona and Illinois.
The Phoenix hospital's director, Sharon Helman, also served as director of the hospital in Hines, Illinois, from 2010-2012. Helman, who has been placed on leave while the investigation moves forward, has denied the claims, which have not been proven.
The Illinois hospital's current director, Joan Ricard, says there was no separate patient waitlist at that facility. She said a spreadsheet was used by the mental health department, but it was a "performance improvement tool" and was not linked to patient appointment scheduling.
"I am not aware of any occurrences of data manipulation here at Hines, past or present, and I have received no evidence or specific facts about data manipulation at the Hines VA," Ricard said in a written statement.
The allegation came from VA social worker Germaine Clarno, who is also president of the union representing the hospital's employees, the American Federation of Government Employees VA Local 781.
She first told CBS News in a report Tuesday that veterans were put on secret waiting lists when they first sought appointments and would not formally be booked into the system until an appointment became available within the VA's maximum wait goal of two weeks.
Clarno told CBS that executives and doctors were seeking "to make numbers look better for their own recognition and for bonuses."
She could not immediately be reached for comment Thursday.
Wednesday's visit by VA auditors had been scheduled before Clarno's allegations, but they did inquire about the allegations, said Hines spokeswoman Charity Hardison.
The Inspector General's Office did not immediately return a call seeking comment Thursday.
Veterans Affairs Secretary Eric Shinseki testified Thursday at a Senate hearing on the Phoenix allegations, which surfaced last month. Facing calls by some Republicans and veterans groups to resign, Shinseki said he was "mad as hell" over the allegations and vowed to hold employees accountable if any evidence of misconduct is uncovered.
