BERLIN, Germany (CNN) -- A Hezbollah militant sentenced to life in Germany for murdering a U.S. Navy diver during the 1985 hijacking of a U.S. jetliner has been freed, officials said. The German government denied on Tuesday the release was related to the freeing of a German hostage in Iraq. Mohammed Ali Hamadi was released Thursday and allowed to return to his native Lebanon on the next day, after qualifying for parole after 19 years in prison, said Ulrich Hermanski, spokesman for the North Rhine Wesphalia state justice ministry. "There was no special treatment," Hermanski said in a telephone interview.