A prostitution scandal involving U.S. Secret Service employees and military personnel in Cartagena, Colombia, has led to the departure of three agency employees and raised questions about supervision and conduct ahead of President Barack Obama’s visit to the Summit of the Americas.

The incident came to light after a dispute over payment between a Secret Service employee and a woman at the Hotel Caribe on April 12 drew the attention of hotel staff and Colombian authorities. Eleven Secret Service employees were recalled and replaced before Obama arrived. Investigators were also examining the involvement of about 10 military personnel. The White House said the president’s security was never compromised.

Two senior supervisors, David Chaney and Greg Stokes, were among the three Secret Service employees forced out or facing dismissal; a junior employee resigned. Eight other employees remained suspended, with their security clearances lifted. The supervisors’ attorney, Lawrence Berger, said the investigation was incomplete and that judgment about their roles was premature. He maintained that nothing reported had harmed their mission or the president’s visit.

The supervisors’ involvement prompted questions about accountability within the agency. Lawmakers briefed on the investigation predicted more departures. Investigators interviewed employees and hotel staff, while military officials conducted a separate inquiry.

The controversy widened after reports emerged that Chaney had joked on Facebook about “checking out” Sarah Palin while assigned to protect her during the 2008 campaign. Palin called the comments embarrassing and criticized the administration’s management. Other lawmakers condemned the conduct, with some Republicans calling for leadership changes or questioning Obama’s management. White House spokesman Jay Carney expressed confidence in Secret Service Director Mark Sullivan and urged patience while the investigations continued.