The accusation in the current issue of Life magazine that Stalin was once a Russian czarist spy is "improbable" and "impossible to verify," Martin E. Malia, assistant professor of History, asserted yesterday.

The "revelation" that Stalin was a spy for the czarist secret police, Okhrana, appears in article by Alexander Orlov, one of the Soviet Union's highest ranking NKVD officers in the 1930's. Orlov offers his story as an explanation for the recent about face of Russian leaders in denouncing Stalin.

Present Russian bosses, Orlov says, have probably discovered only recently "Stalin's guiltiest secret of all." Orlov claims to have learned of the spying activities from a cousin who was a Soviet army commander. He did not reveal it until now, when anti-Stalin sentiment is rising in Russia, for fear of Soviet revenge upon himself and his family in Russia, Orlov explained.

There is no proof for Orlov's statement other than his word, Malia said. If the story is true, he added, it is surprising that no one has discovered it before now.

Malia also attacked the authenticity of a letter claimed by its discoverer to prove Stalin's connection with the czarist regime until 1913. Isaac don Levine, author of the first major biography of Stalin, claims to have found an Okhrana letter, written in 1913, in which Stalin's "spying" activities are discussed.

In Life, Levine gives an account of his discovery of the document and his "proof" of its validity. Malia, however, said that the document is probably a forgery.

Incongruity, he said, also occurs in the wording of the letter, which refers to "Stalin's election to the Central Committee of the party." The term "the Party" is to be a considered post-revolution term for referring to the Communist Party, casting doubt as to whether the letter was actually written in 1913, Malia said.