Ayatollah Khamenei ordered Hariri assassination?

Ynet refers to Lebanese Naharnet which, in turn, copies an article from Newsmax:

Sources familiar with the investigation into the assassination of Rafik Hariri in 2006 told Newsmax that the United Nations Special Tribunal for Lebanon will accuse Iranian Supreme Leader Ayatollah Khamenei of giving the order to murder the former Lebanese prime minister, according to the Lebanese website Naharnet.

So far it sounds like a rumor, but if not, it's a biggy.