Rabbi Moshe Reuven Azman is the Chabad chief Rabbi of Ukraine, one of three rabbis with a claim on the title, and one of two Chabad rabbis with a claim. He is the Rabbi of the Brodski Synagogue in Kiev, the capital of Ukraine.
His election as Chief Rabbi by a group formed by some wealthy Jewish businessmen in October 2005, caused considerable controversy in the Ukraine Jewish community. Azman's election was endorsed by a group of secular Jewish leaders attending a Kiev Jewish conference, but not by any rabbinical authorities. A group of rabbis from the non-Chabad Federation of Jewish Communities attacked the appointment describing it as "illegitimate" and "insulting to the feelings of every believer". 150 secular Jewish leaders from 100 Ukrainian cities and towns later protested the vote as well.
Chabad maintains a Chief Rabbi in Ukraine in opposition to non-Chabad Chief Rabbi Yaakov Bleich. [More at Wikipedia]