A Secret Service agent is buffeted by U.S. President Barack Obama's Marine One helicopter as he departs the White House on Nov., 24, 2013. A long-awaited report released Dec. 20, 2013, concluded that the elite law enforcement agency does not have a widespread problem with its employees engaging in sexual misconduct. (MIKE THEILER/Reuters)

A long-awaited report analyzing the male-dominated culture of the U.S. Secret Service concluded that the agency does not have a widespread problem with its employees engaging in sexual misconduct while on official business.

The findings, released Friday by the Department of Homeland Security’s inspector general, come 1½ years after more than a dozen Secret Service agents and officers were implicated in a prostitution scandal ahead of President Obama’s trip to Cartagena, Colombia. Congress requested the report after agency officials testified that the behavior was an aberration.

The report found isolated cases of misbehavior, and investigators recommended 14 guidelines to identify and address misconduct by employees. Investigators said the agency has implemented 11 of the recommendations.

“Although individual employees have engaged in misconduct or inappropriate behavior, we did not find evidence that misconduct is widespread in USSS,” according to the report, which was obtained by The Washington Post before its release. “Furthermore, we did not find any evidence that USSS leadership has fostered an environment that tolerates inappropriate behavior.”

The report warned, however, that the agency “should continue to monitor and address excessive alcohol consumption and personal conduct within its workforce.” It said most misconduct cases involved excessive alcohol use and unbecoming personal behavior.

Investigators also highlighted a 2010 incident that was “similar to Cartagena but was not thoroughly investigated.” In that case, an unidentified agent was alleged to have consorted with foreign prostitutes while on an international trip and returned to work after a long absence smelling of alcohol, according to his colleagues.

Secret Service spokesman Ed Donovan said late Thursday that the inspector general’s report backs up the agency’s contention that misbehavior is isolated.

“This report confirms what we’ve been saying for two years — that there is not widespread misconduct and there is not an environment that fosters misconduct in the agency,” Donovan said. He said the agency had created a “professionalism reinforcement working group” and implemented 17 more recommendations to improve internal operations dealing with values and standards of employees.

But Sen. Susan Collins (R-Maine) said in a statement that the report shows “a certain subculture at the Secret Service that engages in risky behavior that could put national security and the mission of the Secret Service at risk.”

She added: “Those who participate in the subculture described in this report tarnish the good work of others who do their jobs with honor and integrity.”

The culture evaluation relied largely on an anonymous electronic survey of Secret Service agents. Of the agency’s 6,500 employees, 2,575 completed the survey questionnaire, according to investigators. Of that subset group, 83 percent said they were not personally aware of sexual misconduct akin to the incident in Cartagena.

The office’s acting inspector general, Charles K. Edwards, stepped down Monday as he and his top deputies were under Senate investigation for altering and softening reports to remove information that might embarrass the Secret Service and the Obama administration.

A Senate committee investigating Edwards has been given accounts from whistleblowers of numerous incidents spanning 17 countries in which Secret Service agents allegedly hired prostitutes, visited brothels or engaged in unreported sexual relationships with foreign nationals — all while on duty. The public version of the inspector general’s report, which is partially redacted, makes no mention of that number of incidents.

The report is signed by Carlton I. Mann, who replaced Edwards as acting inspector general.

Secret Service Director Julia Pierson said in a letter last month to the inspector general’s office that her agency was concerned about the methodology the investigators used to compile the report.

Pierson, who became the first female director of the agency last spring, said the survey asked employees to “speculate about the personal, sexual, and potential criminal activities of co-workers” and to respond “through rumor and gossip.”

Pierson also wrote that the agency had implemented a series of new guidelines to improve agency standards before the investigators made their own recommendations. They include expanded ethics training, a new position of chief integrity officer and a table of penalties for specific violations of the employee code of conduct.

“The criticality of the Secret Service’s mission demands that we maintain the highest levels of integrity in our workforce,” Pierson wrote. “I remain committed to investigating and adjudicating all instances of misconduct that are brought to my attention.”

Last month, The Post reported that two senior supervisors in the presidential protection division were removed from their positions after evidence was uncovered that they had sent inappropriate e-mails to a female subordinate. One of the two male supervisors also was found to have created a disturbance at a Washington hotel after leaving a service-issued bullet in the room of a female guest.

The agency has been under scrutiny since April 2012, when hundreds of personnel were sent to Cartagena ahead of Obama’s visit for an international economic summit. Thirteen were found to have brought prostitutes back to their rooms before Obama’s arrival.

The scandal became the most damaging in the Secret Service’s history and raised questions about whether an unprofessional culture of hard-partying agents was risking the nation’s and the president’s security.

The inspector general’s report detailed the punishment meted out to the agents implicated in Cartagena, concluding that Secret Service management treated them appropriately based on the facts in their individual cases. Some agents caught in the scandal said they were treated differently than others found to have hired prostitutes or to have engaged in relationships with foreign nationals in the past, and that managers looked the other way at such incidents when they were not public.

“Of the 13 employees suspected of soliciting prostitutes, 3 employees returned to duty, 6 either resigned or retired, and 4 had their clearances revoked and were removed,” the report said.