Previously, a post here discussed the Lubavitch teaching that Moshiach will be a Misnaged (opponent of Hasidism).
Someone might think that it is an obscure, forgotten teaching, dug up from over two hundred years ago, when the Alter Rebbe was still alive. But that is not exactly the case.
I found some more information about it recently. It is mentioned in the recent book on the seventh Lubavitcher Rebbe by Joseph Telushkin, and he gives a source for it, from the last Rebbe. The late seventh Rebbe himself (!) mentioned it, right in the beginning of his tenure as Lubavitch leader. His version is a bit different than what was posted here previously, but the basic facts are the same.
You can see it here, in a sicha from Chol Hamoed Sukkos 5712 (1951 C.E.), תורת מנחם ד:נג