Updated

At least three more Secret Service agents are expected be fired in the wake of the prostitution scandal, Fox News learned Friday afternoon.

The firings would bring to six the number of people forced out after the incident last weekend in Cartagena, Columbia, where at least one agent allegedly hired a prostitute and brought her back to his hotel.

The agents were there in advance of President Obama’s arrival for an international trade summit.

Eleven agents have been implicated in the incident. Of the six ousted, one was allowed to retire in the wake of the scandal. The rest are on paid administrative leave while the incident is being investigated.

Separately, the lawyer for two Secret Service supervisors said the president’s safety was never at risk and criticized leaks of internal government investigations in the case, signaling a possible strategy for an upcoming legal defense.

More On This...

The Secret Service also briefed congressional officials behind closed doors about details in the incident.

News of the incident, which involves as many as 20 Colombian women, broke a week ago after a fight over payment between a prostitute and a Secret Service agent spilled into the hotel hallway.

A 24-year-old Colombian prostitute told The New York Times that the agent agreed to pay her $800 for a night of sex but the next morning offered her only $30. She eventually left the hotel, she told the newspaper, after she was paid $225.

And the New York Post has published pictures of one of the alleged prostitutes.Pentagon press secretary George Little said Defense Secretary Leon Panetta was getting regular updates on the investigation.

"He understands the level of interest in this issue," Little said. "He has serious concerns about the alleged misconduct."

Little said members of Congress have not yet been briefed on the military investigation but would be "in the near future."

In a letter to Secret Service employees Monday and obtained by the AP, Director Mark Sullivan said the agency had moved in a "swift, decisive manner immediately after this incident was brought to our attention." He praised "the overwhelming majority" of employees who he said had acted with the "highest levels of professionalism and ethical behavior."

"Our job, our mission, our responsibility is to the president, the American people and the individuals we are entrusted to protect," Sullivan said. "This is not just a matter of honor, although this is critical. It is imperative, as part of our sworn duties, to always act both personally and professionally in a manner that recognizes the seriousness and consequence of our mission."

The lawyer for ousted Secret Service supervisors David Chaney and Greg Stokes, Lawrence Berger of New York, said Friday that leaks surrounding the investigations "distort the process."

Regardless of what happened inside hotel rooms, Berger said, it never jeopardized the president's security. Berger said he could not comment on the woman's claims about being paid for sex, but he added, "I don't think anything she has said is material to any of the issues I am pressing with my clients."

"Nothing that has been reported in the press in any way negatively or adversely impacted the mission of that agency or the safety of the president of the United States," Berger said.

Chaney and Stokes were forced out of the agency Wednesday. A third agent, who has not been identified and was not a supervisor, resigned.

On Chaney's Facebook account, which was made inaccessible on Friday, Chaney joked about his work with former Republican vice presidential candidate Sarah Palin while he was protecting her in 2008.

The AP published a photograph it took of Chaney working in Palin's protective detail in October 2008 during a campaign rally in Carson, Calif.

"I was really checking her out, if you know what i mean?" Chaney wrote after a friend commented on the picture posted in January 2009 on Chaney's Facebook account.

Speaking on Fox News late Thursday, Palin said the joke was on Chaney.

"Well, check this out, buddy — you're fired," she said.

All 11 of the Secret Service employees have had their top-secret security clearances lifted.

The agency's investigation has included interviews of agents and hotel staff. Rep. Peter King, chairman of the House Homeland Security Committee, said this week that investigators in Colombia have not been able to interview the women.

The affair has also prompted a military investigation of the service members, including six members of the Army, two Navy Explosive Ordinance Disposal technicians, two Marine dog handlers and an Air Force airman.

An Air Force colonel and a military lawyer were also dispatched to Colombia this week. Under the Uniform Code of Military Justice, patronizing prostitutes is a crime for military personnel. It is referred to as "compelling, inducing, enticing or procuring a person to have sex in exchange for money; or receiving money for arranged sex."

Officials from U.S. Southern Command, which organized the military role for the security operation, have not provided details of its probe beyond saying that at least some of the military members violated curfew and may have been involved in "inappropriate conduct."

White House press secretary Jay Carney has said it is "preposterous to politicize" the issue, responding to criticism from Alabama Sen. Jeff Sessions and Palin, who have said the allegations reflect poor management of the government under Obama.

Palin described the affair Thursday as a "symptom of government run amok."

"It's like, who's minding the store around here?" Palin said.

Carney said Obama had not had any conversations with Secret Service Director Sullivan but wouldn't rule out that they might speak soon.

The Associated Press contributed to this story.