The late FBI director J. Edgar Hoover was not as tightfisted with secret warning signals about Pearl Harbor as he has been made out to be, according to declassified documents made public this week.

In the months before the surprise Japanese attack in December, 1941, the FBI informed the Office of Naval Intelligence and the Army's intelligence division about a questionnaire obtained from a double agent that reflected intense Japanese interest in the defense installations at Pearl Harbor in the Hawaiian Islands and the Army airfields on the island of Oahu.

The military apparently viewed the information with no greater alarm than did the bureau.

The FBI released the long-secret records this week in response to a recent article by two Michigan State University historians stating that Hoover kept the details to himself and passed on to President Franklin D. Roosevelt only "a harmless part of the questionnaire," a part used to impress the White House with the bureau's expertise, according to the historians.

Assistant FBI Director Roger S. Young, who released six internal FBI memos bearing on the controversy, said he thought they would clear Hoover of the charge that he had a "hand in the intelligence bungles" that lulled the United States before the Japanese attack.

The documents--dated between Sept. 30 and Nov. 8, 1941--deal with the activities of a Yugoslav playboy named Dusko Popov who became a spy for German intelligence in 1939 (code name: Ivan) and then quickly transformed himself into a double agent for the British (code name: Tricycle).

He came to the United States in the summer of 1941 with instructions to set up a Nazi spy network. He was also instructed to get the answers to a questionnaire that the Germans had prepared in concert with their ally, the Japanese.

A third of the questionnaire--which had been reduced to the size of dots in the "i's" of a telegram Popov brought with him--dealt with requests for information about the defenses on Oahu, including Hickam, Wheeler and Kaneohe airfields, the piers and dry docks at Pearl Harbor and the depths of the water there. Popov turned the telegram over to the FBI on his arrival in New York.

Historians John F. Bratzel and Leslie B. Rout Jr. disclosed in last December's issue of the American Historical Review that Hoover told the White House only about the microdots, and an innocuous portion of what they said, to illustrate how the FBI was staying on top of the latest methods of German espionage.

Bratzel and Rout also reported that Hoover apparently failed to tell military intelligence officers any more of the questionnaire's contents although they might "have better appreciated its importance."

But one of the newly declassified documents, a Sept. 30, 1941, FBI memo for D.M. Ladd, then head of the bureau's intelligence division, said that "information contained in the questionnaire furnished Popov by the Germans" had been paraphrased and given to U.S. naval and Army intelligence. Another document showed that further details on the enemy inquiries concerning Pearl Harbor were supplied to naval intelligence.

The Navy, in turn, asked the FBI to pick one particular item--it turned out to be about anti-torpedo nets--so that disinformation could be prepared for Popov to feed back to the Germans.

U.S. intelligence historian Thomas F. Troy said yesterday that the big U.S. worry at the time was sabotage. The questionnaire contained no clear hint that a Japanese air attack could be expected. Popov wrote before his death that he had warned the FBI of that, too, but this question remains to be settled as declassification proceeds on the 19 volumes of FBI records about Popov.