Written to the interior ministry in 1895, a month after he was sentenced for treason, the letter will be sold by Sotheby's in Paris on May 29 and is expected to fetch between €100,000 and €150,000 ($130,000 and $190,000), the auction house said in a statement.
Dreyfus (1859-1935) – a 35 year-old Jew from the Alsace region of eastern France which was at the time occupied by Germany – was found guilty in 1894 of passing secret information to the German military attaché in Paris and sentenced to life imprisonment at the infamous Devil's Island penal colony.
In 1898 the writer Emile Zola published his famous "J'accuse" letter to the president of the day naming officials who framed Dreyfus, and the next year he was brought back for a second trial and then officially pardoned – though not cleared of the charges.
Dreyfus was not fully rehabilitated and restored to his rank in the army until July 12, 1906, when the high court of appeal overturned the original verdict.