29-year-old Rosberg was born in Germany but raised in Monaco. His parents are 1982 F1 champion Keke Rosberg, who was born is Sweden but raced under the Finnish flag, and his German wife Sina.
Nico has competed as a German since entering Formula One in 2006, but the Mercedes driver also holds Finnish nationality and describes the Monaco Grand Prix as his home race.
And ahead of his other home event - the upcoming German Grand Prix at Hockenheim - Hamilton was asked what kind of support Rosberg would receive, and questioned just how strong his team-mate’s claims to that nationality really are.
“To be honest, Nico has never been in Germany, so he’s not really German," said Hamilton "I remember when we used to race during karting, he never stood next to a German flag – not ever.
“We would have to go on the start line and all the drivers would have to stand next to a grid girl in a line. The girls would be holding the flags or a sign saying Hungary or whatever, and he always stood by the Monaco one. He never stood by a German flag.
"He is German-Finnish-Monaco-esque, or whatever. So it would be great to win in Germany.”
British Grand Prix winner Hamilton heads to the German event just four points behind championship leader Rosberg, who suffered his first DNF of the campaign at Silverstone.