(CNN) -- The White House has ignored a deadline to provide answers to a senior Senate Republican about the Secret Service prostitution scandal, an aide to Sen. Charles Grassley said Friday.
Grassley wants details about an internal administration investigation into any possible role that White House advance staff members may have had in the incident.
The Secret Service has been rocked by allegations of transgressions by its agents, including reported heavy drinking and consorting with prostitutes this month before President Barack Obama arrived in Cartagena, Colombia, for the Summit of the Americas.
On Monday, Grassley sent a letter to White House Counsel Kathryn Ruemmler, demanding answers to how and why her office conducted the review.
The Iowa Republican made clear that he was not satisfied with White House Press Secretary Jay Carney's characterization that the review found there was "no indication of misconduct" by the White House staffers, who flew to the Latin American country to prepare for Obama's visit.
In his letter, which contained 14 questions about the review, Grassley said he wanted the answers by Thursday. However, the deadline came and went without any word from the White House. E-mails and phone calls to the White House from Grassley's staff members Thursday were ignored, Grassley aide Beth Levine said.
The White House declined to comment about why the material had not been sent to Grassley.
Grassley is the top Republican on the Judiciary Committee, which held a hearing this week on the unfolding scandal. At the hearing, he complained to Homeland Security Secretary Janet Napolitano that his requests for information from her department are routinely ignored or delayed.
Separately, Grassley called for the inspector general of the Department of Homeland Security, the parent agency of the Secret Service, to investigate the White House staff. Democrats dismissed that idea as politically motivated.
Grassley is considering what steps he can take next to get the answers, Levine said.
His power to compel the answers is somewhat limited. Unless Judiciary Committee Democrats agreed to subpoena the information, which is unlikely in this political climate, Grassley may have only his ability to stir a public outcry to get the White House to answer his questions.