WASHINGTON, May 9 (Reuters) - The United States on Tuesday imposed sanctions on a son of former Mexican drug kingpin Joaquin "El Chapo" Guzman, the Treasury Department said. El Chapo, who was leader of the Sinaloa Cartel, is currently serving a life sentence in a U.S. prison. Mexican President Andres Manuel Lopez Obrador has denied the presence of fentanyl labs in the country, alleging it comes from China. Guzman Lopez's cousin, Saul Paez Lopez, was also sanctioned for his alleged role in coordinating drug shipments. Washington also sanctioned Mario Esteban Ogazon Sedano, saying he purchased precursor chemicals from Ludim Zamudio Lerma to operate drug labs.

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