Yuri V. Trifonov, a Stalin literature prize winner who became one of the Sovit Union's most respected and politically daring authors for writing openly of Stalin's terror, died here Saturday at age 55, his family has reported.

Mr. Trifonov, whose novellas and stories in the past 15 years dealt with the moral torments still echoing from the time of the great purge, had undergone a kidney operation Thursday and died of complications, the sources said.

His best-known work here was "The House on the Embankment," a complex short novel that appeared in 1976 and told of the guilt and long-hidden agonies of a man who in his youth failed to defend his college professor and intended father-in-law from false accusations by the security police.

The story was an instant sensation and has become one of the most treasured works of the Brezhnev era, when Communist Party censors cracked down hard on authors trying to discuss the impact of those times on Soviet society today.

Mr. Trifonov's first book, "Students," a novel about university life in the post-war years and published in 1950 when he was 24, received the Stalin Prize.

A solidly built man with thick-lensed glasses veiling soft blue eyes, Trifonov kept his distance from politically active writers with the liberal-minded artistic community, maintaining low profile that masked an increasing dedication to probing into the past. The importance of understanding what happened in Stalin's time and earlier, during the red terror of the 1920s, is a major theme in Trifonov's works. He was considered a master of the short novel form, frequently using flashbacks, interior monologues, and scraps of documents or letters -- some real, some fictional -- to suggest the ambiguities of Soviet existence.

Mr. Trifonov's survivors include a wife and 2-year-old son.