In part from a previous version of the Wikipedia page [1] on the Voynich Manuscript

Developed a theory that it is a Manchu-language document written in plaintext.

The Polish Press Agency featured an article on the topic in October 2003.

More information here [2] (last updated 2004, checked October 2018) and there is an extensive discussion here [3].

His page on the Polish Wikipedia is [4]