Maybe you’re thinking about the Man from Taured?

a Caucasian man was arrested at the airport upon entering Japan because they couldn’t classify his passport and didn’t know the issuing country.

When he is shown a map so he can tell where he is from, he points to Andorra and calls it “Taured”. He cannot understand why no one knows about this country that, according to him, has existed for 1,000 years.

He is taken to a hotel and two police officers guard his room while the case is further investigated. When you go to visit him again, the room is empty and there is no trace of the man from Taured. Did he come from a parallel universe?

This is translated from the German podcast summary. Wikipedia displays it slightly differently:

https://en.wikipedia.org/wiki/John_Zegrus

https://hoaxilla.com/hoaxilla-361-mann-aus-taured/