The embattled head of the U.S. Drug Enforcement Administration (DEA), Michele Leonhart, will retire from the agency next month, the Justice Department announced on Tuesday.

She faced mounting pressure to resign from members of Congress who questioned her competence in the wake of a scathing report by the department's Office of the Inspector General that detailed allegations that DEA agents attended sex parties with prostitutes in Colombia.

Attorney General Eric Holder said Leonhart, a career drug agent who has led the agency since 2007 and is the second woman to hold the job, would leave the agency in mid-May.

"Michele has led this distinguished agency with honor, and I have been proud to call her my partner in the work of safeguarding our national security and protecting our citizens from crime, exploitation and abuse," he said in a statement. "I have no doubt that the women and men of the DEA will continue to perform their duties with the utmost integrity, professionalism and skill."

Leonhart was widely criticized for her response to the report on the DEA, and a group of lawmakers said in a statement that she was "woefully unable to change" the agency's culture.

After a disastrous appearance before the House Oversight Committee last week, a majority of its members said they had lost confidence in her. In a statement, they said she "lacks the authority and will to make the tough decisions required to hold those accountable who compromise national security and bring disgrace to their positions."

The report that jeopardized Leonhart's job recounted allegations that drug agents attended sex parties with prostitutes, some provided by local drug cartels, in a foreign country. The DEA said the incidents happened in Colombia. No DEA agents who were at the parties were fired. Instead they received suspensions of two to 10 days.

The no-confidence statement was signed by 13 House Democrats and nine Republicans, including Chairman Jason Chaffetz of Utah and the committee's top Democrat. Chaffetz went a step further, calling for Leonhart to resign or be fired.

White House spokesman Josh Earnest wouldn't comment Tuesday on reports that Leonhart was set to leave the agency, only reiterating that the White House had "concerns about the material that was presented in the report that raised legitimate and serious questions about the conduct of some DEA officers."

"The president, as you know, maintains a very high standard for anybody who serves in his administration, particularly when it comes to law enforcement officials. And the … report raised serious concerns about that conduct," he said.

Leonhart canceled an appearance to receive an award Tuesday from sponsors of the Border Security Expo, a trade show in Phoenix for government contractors. Doug Coleman, the DEA's special agent in charge in Phoenix, accepted on her behalf.

Robert Bonner, a former DEA administrator and Customs and Border Protection commissioner, told the luncheon audience that she was being unfairly blamed for agents' misconduct. He said last week's House hearing presented a "jumbled and distorted" picture of the agency, much of it untrue.

"Sadly, what we're witnessing in Washington is gotcha politics in action," he said. He said he hoped Leonhart stays on the job, adding that she lacked authority to fire agents with civil service protections and shouldn't be blamed for punishments that were perceived as too light.

Lawmakers have criticized the DEA and Leonhart for what they described as lenient punishments for agents accused of wrongdoing.

She was previously the target of online petitions calling for her ouster after she distanced herself from the administration's stance on legalized marijuana — a hands-off approach that lets states legalize marijuana as long as it is regulated. Marijuana remains illegal under federal law and is classified by the DEA as a Schedule I drug, like heroin and peyote.

Drug reform advocates chastised Leonhart in 2012 after she refused to tell a House subcommittee whether she thought heroin is more dangerous than marijuana. She repeatedly skirted the question, posed by Jared Polis, D-Colo., by answering, "I believe all illegal drugs are bad."

She declined to fully endorse sentencing reform efforts supported by the Justice Department, and the DEA has been criticized by privacy advocates for its use of a sweeping database of phone calls made from the United States to certain foreign countries. The agency acknowledged that database in a court filing involving a man accused of conspiring to illegally export goods and technology to Iran but said it was no longer in use.

During her tenure, the agency was responsible for a variety of notable criminal cases, including assisting in the 2014 capture of Mexico's Joaquin "El Chapo" Guzman, long considered one of the most powerful drug traffickers in the world.

There were also scandals, including the arrest of Daniel Chong, a California college student who was left alone in a holding cell for five days without food or water. The April 2012 incident left him in grave physical health and led to a $4.1 million settlement and nationwide changes in the agency's detention policies.

Al Jazeera and The Associated Press