Secret Service Agent Accused of Affair Kills Self Rafael Prieto allegedly in undisclosed relationship with foreign citizen By Matt Cantor, Newser User Posted Nov 2, 2012 7:12 AM CDT 13 comments Comments A Secret Service agent has apparently committed suicide. (Shutterstock) (Newser) – A Secret Service agent appears to have killed himself as authorities investigated allegations of an unreported affair with a foreign national. Rafael Prieto was found dead Saturday, Politico reports; an official cause of death hasn't yet emerged. Prieto, who was reportedly estranged from his wife, had been undergoing an investigation into his relationship with a Mexican woman. For security reasons, the Secret Service requires relationships with foreign citizens to be disclosed, though officials don't believe Prieto was passing information to the woman. A colleague told authorities about the relationship following the Secret Service's Colombian prostitution scandal, which has prompted heightened concern over such matters. When he was questioned, Prieto acknowledged the affair. He was discovered in his car with the motor running, the AP reports. "Rafael Prieto had a distinguished 20-year career with the Secret Service that was marked by accomplishment, dedication, and friendships," says a spokesman. "The Secret Service is mourning the loss of a valued colleague."