The head of the Secret Service -- the police agency that protects US President Barack Obama -- is retiring, a spokesman said Friday, less than a year after the elite squad was hit by a sex scandal.
Mark Sullivan is "retiring as of the 22nd of February," Secret Service spokesman Brian Leary told AFP, noting he had overseen 23 national security events, including Obama's inaugurations in 2009 and 2013.
Sullivan, who took up his post in May 2006, saw the end of his term marked by a series of setbacks, including a prostitution scandal that erupted last April as agents helped prepare Obama's visit to a summit in the Colombian port city of Cartagena. Nine officers subsequently resigned or retired.
Hundreds of Secret Service agents typically travel with, or before Obama when he goes overseas, in a huge security retinue.
"I want to thank Mark Sullivan for nearly 30 years of service to our nation at the United States Secret Service, a tenure that saw the agency protect five first families including my own," Obama said in a statement.
"Since 2006, as director, Mark has led the agency with incredible dedication and integrity. The Secret Service is best known for protecting our nation's leaders, but every day they also protect the American people," he added.
Last year's incident in Colombia, however, was embarrassing for the Obama administration and led to allegations that national security or the president's safety might have been compromised.
Sullivan had to testify in Congress to assure that no security breaches were committed during the scandal.
The Secret Service later announced it had toughened the rules regulating behavior of its agents abroad, including the consumption of alcohol.
Sullivan had earlier found himself in the hot seat in 2009 after socialite and reality star Michaele Salahi and her husband Tareq breezed through White House security at a state dinner for Indian Prime Minister Manmohan Singh.