The Secret Service scandal erupted last weekend after it was revealed that 11 agents, along with military personnel, drank heavily and caroused with prostitutes while they were setting up security ahead of President Obama's recent trip to Cartagena.

The Secret Service launched an immediate investigation, and six of the 11 agents have already left – or will soon leave – the agency. But the incident has led to questions about whether the agents' behavior at any time compromised the president's safety.

Some are wondering if the scandal's scope isn't broader than just the Secret Service and the Pentagon. On Friday, Sen. Charles GrassleyChuck GrassleyFriends, foes spar in fight on Trump’s Supreme Court nominee Live coverage: Day three of Supreme Court nominee hearing Live coverage: Day two of Supreme Court nominee hearing MORE (Iowa), senior Republican on the Senate Judiciary Committee, asked administration officials – including Secret Service Director Mark Sullivan – whether any White House staffers were working alongside the agents in the lead up to Obama's visit.

Grassley said members of the White House Communications Agency (WHCA) and the White House Office of Advance "ordinarily" accompany the Secret Service ahead of the president's travels.

"Did the Secret Service reserve rooms … for representatives of the WHCA or the White House advance team?" Grassley asks. "If so, have records for overnight guests for those entities been pulled as part of the investigation … ?"

Lieberman on Sunday said the Obama administration should take Grassley's questions seriously.

"That's an important question, and the White House ought to be taking Grassley's inquiry, not defensively, but making sure that they answer the questions."

Lieberman said the White House also "ought to be conducting its own internal investigation of White House personnel who were in Cartagena, just to make sure that none of them were involved in this kind of inappropriate behavior." 

Lieberman said he and Sen. Susan CollinsSusan CollinsFive takeaways from Labor pick’s confirmation hearing ObamaCare repeal faces last obstacle before House vote Live coverage: Day three of Supreme Court nominee hearing MORE (Maine), senior Republican on the Homeland Security panel, plan this week to request information from the Secret Service about whether the incident is an isolated event or evidence of broader cultural problems at the agency.

"They were not acting like Secret Service agents" he said. "They were acting like a bunch of college students away on spring weekend."