MIAMI (AP) — A Colombian businessman was carrying a letter from Venezuelan President Nicolas Maduro accrediting him to Iran's supreme leader when he was arrested on a U.S. warrant last year, according to a new court filing in a politically charged corruption case ratcheting up tensions with the South American nation. Attorneys for Alex Saab made the filing in Miami federal court Thursday just hours after prosecutors in the African nation of Cape Verde said they granted the 49-year-old Colombian house arrest as he fights extradition to the U.S.