Two of the Secret Service personnel are paid at one of the higher levels of the federal pay scale, meaning they are senior officials potentially in supervisory positions, according to a congressional official with knowledge of the investigation.

The accusations are triggering scrutiny of the culture of the Secret Service — where married agents have been heard to joke during aircraft takeoff that their motto is “wheels up, rings off” — and raising new questions at both the agency and the Pentagon about institutional oversight at the highest levels of the president’s security apparatus.

“We are embarrassed,” Gen. Martin E. Dempsey, the chairman of the Joint Chiefs of Staff, told reporters in a briefing at the Pentagon. “We let the boss down, because nobody is talking about what went down in Colombia other than this incident.”…

“I find this to be so appalling,” said Sen. Susan Collins (R-Maine), the ranking member of the Senate Homeland Security and Governmental Affairs Committee. “I can’t help but think, what if the women involved had been spies?. . . It’s such a breach of trust, and it’s virtually unbelievable. I’m truly shocked.”