What explorer believed that Columbus did not land in Asia?

Almost anyone who at the time knew something about navigation. First the Portuguese had - even before he started out - worked out that Columbus could never find China where he thought it would be; and later on the Spanish experts decided the same thing, but Queen Isabella decided to let him have a shot at it anyway.

Most famously, the cartographer (not explorer, by the way) Amerigo Vespucci also worked out that what Columbus had found could not possibly be China. He never called it "America" himself though, nor did the people around him. The very first mention of "America" is on a map made in Bristol, England, showing the parts of North America that had been discovered by an expedition funded by a British tradesman called Richard Ameryk.