The Lufu language of Nigeria is a nearly extinct language still spoken by some elders among the 2,000-3,000 Lufu in Takum Local Government Authority, Taraba State; its speakers have mostly shifted to Jukun. It is reported to have been close to Lufu and Bibi. According to the Vienna Yukuben Project (http://www.univie.ac.at/linguistics/yukuben/), it and Bete probably belong together in the Southern Jukunoid subfamily of Niger-Congo; the Ethnologue lists it as unclassified.
Bibliography
Crozier, David H. and Roger M. Blench, editors. 1992. An index of Nigerian languages. Abuja, Nigeria and Dallas: Nigerian Language Development Centre, Department of Linguistics and Nigerian Languages, University of Ilorin, and Summer Institute of Linguistics.