Mexican President Andres Manuel Lopez Obrador on Wednesday urged the United States to reveal the whereabouts of a notorious drug trafficker whose name has disappeared from the U.S. prison register. Edgar Valdez Villarreal, a Mexican-American nicknamed "La Barbie" for his fair complexion, was captured by Mexico in 2010 and extradited to the United States, where he was sentenced to 49 years in prison. Media reports recently revealed that the former henchman of the Beltran-Leyva cartel no longer appears in a search of the Federal Bureau of Prisons' online register of inmates. "The United States government has to clear it up as soon as possible," Lopez Obrador told reporters, adding that Mexico was awaiting a response. "We're going to continue asking them," he added, describing the case as "odd" since the trafficker still had many years to serve unless he struck a deal with the U.S. authorities. The Bureau of Prisons told AFP that the Texas-born Valdez "is not currently in the custody" of