Deubner was born in Ilensko-Tobolsk village, Tobolsk Governorate, Russian Empire, into a family of Catholic priests of the Byzantine rite, Ivan Deubner, his father having converted to Catholicism in 1903.
Ordained a priest in Constantinople in 1926 by Bishop Michael Mirov, Exarch of the Bulgarian Greek Catholic Church he was sent to work with Russian immigrants in the south of France, under the leadership of the priest Lev Gillet, OSB, serving in the House for Russian children in Nice.
In 1928 Alexander Deubner and Gillet abandoned Catholicism and joined Orthodoxy[1] under the jurisdiction of the Orthodox Metropolitan Eulogius (Georgievsky) of the Western European Exarchate of Russian Orthodox parishes, but shortly after, at the request of his (Catholic) father suffering exile within Russia, Alexander returned to Catholicism, working in the Commission "Pro Russia" and being secretary of Bishop Michel d'Herbigny.
[2][3] In 1932 he left the ministry for 'not very honourable' reasons and went to Berlin where he was denounced as a Soviet spy, but in 1933 he returned to Rome, and shortly went to Paris.
He was held in Butyrka prison in Moscow and was sentenced to 10 years but he died in the Gulag on 5 May 1946.