Sad story. And, sad to say, fake news.
Because there is no such thing as a multiple person.
Multiple is often misused this way. You want Many people or Numerous people or Multitudes of people. But multiple means “involving several things.” Each of the things you call multiple is a single thing. This is why you use the adjective multiple — to specify several of the single thing you’re talking about.
In fact, if this isn’t already confusing enough, it is possible to talk about a people — singular — like the American people — but you would have to say Multiple peoples — the Yanks, the Brits, and the French, for example — not Multiple people.
(If there were multiple people — I mean, if a person could be multiple — would they be clones? Or zombies? Or [other]? Attack of the Multiple People — in theatres June 7!)
English Is A Complicated Language 