Wikipedia article reads as following:
A famous story goes that in 1918, after the October Revolution, Bernstein was arrested in Odessa by the Cheka (Bolshevik secret police). He was ordered to be shot by a firing squad because he was a legal advisor to bankers. As the firing squad lined up, a superior officer asked to see the list of prisoners' names. Discovering the name of Ossip Bernstein, he was asked whether he was the famous chess master. Not satisfied with Bernstein's affirmative reply, the officer made Bernstein play a game with him. If Bernstein lost or drew, he would be shot. Bernstein won in short order and was released. He escaped on a British ship and settled in Paris.
Is this story entirely true? Any sources are there to support it?