Secret Service agents and managers have engaged in sexual misconduct and other improprieties across a span of 17 countries in recent years, according to accounts given by whistleblowers to the Senate committee that oversees the department.

Sen. Ronald H. Johnson (Wis.), ranking Republican on a Homeland Security subcommittee, said Thursday that the accounts directly contradict repeated assertions by Secret Service leaders that the elite agency does not foster or tolerate sexually improper behavior.

The allegations come in the wake of a prostitution scandal last year in Cartagena, Colombia, that roiled the Secret Service and prompted numerous reviews of its male-dominated culture. In a subsequent episode, The Washington Post reported this week, two supervisors were cut from President Obama’s security detail after allegedly sending sexually explicit e-mails to a female agent.

Johnson said that one of those disciplined supervisors, Ignacio Zamora Jr., had helped lead the internal investigation into the April 2012 incident in Cartagena, where more than a dozen agents engaged in a night of heavy drinking and carousing with prostitutes ahead of a presidential visit.

One person involved in security in Cartagena said Zamora was chosen for the review because he served as the “second supervisor” on the trip, and was among the managers responsible for the security effort in advance of Obama’s arrival for an international summit. The agency discovered Zamora’s e-mails to a female subordinate after he accidentally left a bullet behind in a woman’s room at the upscale Hay-Adams hotel in Northwest Washington.

Two Secret Service supervisors have been removed from the president's detail for alleged inappropriate behavior. (Reuters)

Johnson said in a statement that letting Zamora investigate Cartagena amounted to “the fox guarding the hen house.”

Secret Service spokesman Ed Donovan hung up on a reporter seeking comment Thursday on Zamora’s role and other allegations. An attorney representing Zamora declined to comment.

White House officials also declined to comment.

After the Cartagena scandal, the agency adopted new policies banning the consumption of alcohol 10 hours before employees report to work and limiting consumption to “moderate amounts” during off-duty hours. Agents and officers cannot drink alcohol when stationed at the hotel of the public official they are assigned to protect.

Johnson declined to elaborate on the specifics of the whistleblower allegations. But two people briefed on the accounts said they include agents and managers hiring prostitutes, visiting bordellos on official trips, having extramarital affairs on the road, and having both one-night stands and long-term sexual relationships with foreign nationals that were not properly reported.

Hiring prostitutes and having sexual relations with foreign nationals are both forbidden by Secret Service policy governing the top-secret security clearances needed for a service job.

One whistleblower who has shared his account with Johnson’s committee told The Post on Thursday that senior management was fully aware of agents hiring prostitutes on foreign and domestic trips.

In one incident in November 2009, the whistleblower said, a crew of more than 70 agents was waiting on a military transport plane to depart Thailand after a rest stop in the country before heading to South Korea.

One of the agents was missing, and to avoid a delay, a supervisor agreed to stay behind to retrieve him from a Thai brothel, where he was found intoxicated. Senior management agreed to transport the agent back to the United States at great expense on a commercial flight. He faced no punishment, the whistleblower said.

Obama visited South Korea in November 2009 as part of an eight-day Asian trip that also included stops in Japan, Singapore and China.

In the wake of Cartagena, Homeland Security Inspector General Charles K. Edwards launched a review of the Secret Service’s culture and behavior. Johnson and Rep. Jason Chaffetz (R-Utah), chairman of the national security subcommittee of the House Committee on Oversight and Government Reform, wrote to Edwards on Thursday asking why they have yet to see a final report, which is due to become public in coming weeks.

“A serious and robust investigation should have revealed facts within weeks, allowing corrective action to be swiftly implemented with Congressional oversight,” the two members wrote.

Johnson said he has concerns about whether the inspector general’s review will be thorough. He also said the Department of Homeland Security has been notoriously soft and has redacted damaging information in its public assessment of the Secret Service’ s handling of problems.

“This type of behavior jeopardizes the security of the President of the United States and makes U.S. government personnel susceptible to coercion and blackmail,” Johnson said in his statement.

In the Hay-Adams incident in May, people briefed on the case said, hotel managers notified the Secret Service after Zamora allegedly tried to reenter a woman’s room where he had mistakenly left behind a government-issued bullet from his service weapon. He had met the woman at the hotel bar before joining her in her room, the people said.

A follow-up investigation revealed that Zamora and another supervisor, Timothy Barraclough, had each sent sexually explicit e-mails to a female agent, the people briefed on the case said. Officials have removed Zamora from his position and moved Barraclough off the detail to a separate part of the protective division.