The discovery of the notorious "Zinoviev Letter" stashed away in the back vault of the Harvard Law School Library has led historians to the exact identity of the man who forged the letter and virtually annihilated the British Labor Party during the 1920's.

William E. Butler, the Law School research associate who discovered photonegative plates of a Russian text of the letter last month, said yesterday it is now "incontestable that the Zinoviev Letter is a forgery and a fraud."

The letter was the key element in a lurid political intrigue centering around the heated British elections in 1924. Coming at the height of the "Red Scare," it purports to be from Grigori Zinoviev, President of the Communist International in Moscow, and instructs the British Communist Party to establish cells in the army and support the Labor Party.

After Butler announced his discovery in the January issue of the Harvard Library Bulletin, reporters from the Sunday Times of London began a search for someone who could identify the handwriting on the Harvard photo-plates.

Handwriting Identified

On Feb. 15, the Sunday Times disclosed that the handwriting has been positively identified as that of Captain Sydney Reilly, a British intelligence agent known as "The spy who has never been known to make a mistake."

The identification of Reilly brings to a close the search for the forger who, British liberals claim, caused the Labor party to lose the 1924 election and fall into disgrace for nearly ten years.

But the resolution of one mystery has only led to the creation of another, Butler says.

Along with the text of the forged Zinoviev letter. Butler also discovered what purports to be "secret minutes" of a Soviet Comintern meeting. The minutes were intended to complement the text of the letter.

The minutes are also written in Reilly's hand and give a detailed account of plans not only to support the British Labor party but also several other liberal movements, including the LaFollete-led Progressive Party in the United States.

"I'm beginning to think the secret minutes tell us more about the forgers and their plot than the letter does," Butler said yesterday. "It is possible that the forgers, in developing their scheme, had in mind influencing both the British and American elections in 1924," he added.

History of Intrigue

Captain Reilly, the now identified forger, has a marvelous history of spy intrigue in Europe which shows he was capable of planning a large scale campaign to discredit Leftist parties.

Born in Russia, Reilly had been an intelligence officer for the Czarist government working with Rasputin. He was involved in an early plot in 1918 to assassinate Lenin and became involved with anti-Bolshevik groups in Europe.

As a British spy, he gained access to Comintern secret files so that heknew not only the style of Zinoviev's letters, but also the language and the personalities who might be involved, Butler said.

When the Zinoviev letter finally broke into the British press two days before the 1924 elections, several copies were known to be circulating among Western intelligence circles in Europe.

Major Charles D. Westcott, the American consul in Paris, reported to Washington that he had received copies of the letter and the secret minutes in the summer of 1924-a few months before the American elections.