The alleged author of a CIA manual that recommends violence to "neutralize" public officials in Nicaragua is a hard-drinking, Korean and Vietnam war veteran who calls himself John Kirkpatrick, sources in the Nicaraguan rebel movement said yesterday.

Nicknamed "Juanito," the American author of a 90-page manual entitled "Psychological Operations in Guerrilla War" was described as of Irish or Scottish descent, an older man who apparently had taught at a military college. He told members of the Nicaraguan Democratic Force [FDN], the largest rebel group, that he was a veteran of Korea as well as Vietnam and that his name was John Kirkpatrick, the FDN sources said.

A classified intelligence report also revealed that Defense Department officials apparently knew as early as July 1982 that Nicaraguan rebels funded by the United States had killed local officials, burned crops and otherwise engaged in terrorist activities.

The classified Weekly Intelligence Summary prepared by the Defense Intelligence Agency, dated July 16, 1982, reports that "insurgent incidents" over the previous four months included "attacks by small guerrilla bands on individual Sandinista soldiers and the assassination of minor government officials and a Cuban adviser." The document was provided to The Washington Post by John Kelly, editor of Counterspy magazine, who said it was leaked to him.

The revelations appeared certain to fuel the controversy over political violence in Nicaragua, where rebels, who President Reagan calls "freedom fighters," are trying to overthrow the leftist Sandinista government.

The CIA and the Defense Department refused to confirm or deny either report, citing the need to protect classified information.

The secret DIA document, in a four-page section entitled, "Insurgent Activity Increases in Nicaragua," said the rebels had showed new strength between March and July 1982. Although it noted charges that the rebels are "U.S.-backed forces," it in no way confirmed this.

However, subsequent revelations have shown that Reagan authorized CIA aid to the rebels beginning in November 1981, and major funding was revealed to congressional oversight committees in December. He signed an executive order that December saying no U.S. government employe "shall engage in or conspire to engage in assassination."

The intelligence summary said 106 "insurgent incidents" in Nicaragua between March and July 1982 involved sabotage of highway bridges, sniper fire and attacks against small military patrols, and the burning of a customs warehouse and crops and attacks on soldiers and the assassinations.

The summary estimated antigovernment rebel strength at about 1,000 active fighters and said the FDN force of about 800 included a "terrorist group" called the "15 September Legion." Named for Nicaragua's independence day, the legion was "composed of a small number of commandos believed to be operating out of Honduras" and had claimed responsibility for several airline bombings and hijackings, the report said.

It is not clear whether Reagan saw the summary, which Kelly said circulates among about 100 top intelligence officials including CIA Director William J. Casey and Cabinet chiefs.

Administration officials, asking not to be identified, earlier said the manual on political violence in Nicaragua was a draft by "an overzealous freelance," an independent contract employe, and that they had "a suspect" author but refused to name the person. They said the document had never been authorized for release.

But Edgar Chamorro, a member of the FDN Directorate, said in a telephone interview from his home in Miami that about 2,000 copies of the manual were provided to him in November 1983 when he was responsible for the group's propaganda.

According to Chamorro and other FDN members interviewed by telephone, "Juanito" was an American expert in counterinsurgency who worked with them at their bases in Honduras for several months last year.

Chamorro said that the man often was critical of the generals and other high officials who had run the Korean and Vietnam wars, that he drank heavily and identified closely with the psychological tactics he had studied.

"He wanted to infiltrate the enemy and identify with the enemy and be one of them," Chamorro said.

The manual was poorly translated into Spanish from "Juanito's" English language notes and contained several references that must seem obscure to the average anti-Sandinista combatant. Its references range from Aristotle to the Huk insurgents in the Philippines.

"I know that people did not read it," Chamorro said. He said most of the copies he received were used in a special course on psychological warfare for middle-level commanders. Some of the rebels objected to it at the time, he said.

"It had concepts that were getting very close to the enemy's," Chamorro said. The author advocated "tactics that I found very offensive -- shocking," Chamorro said.

"When I saw this book I saw there were two paragraphs that were offensive: the one about hiring criminals and the one about creating martyrs on pages 70 and 71," Chamorro said. "We destroyed those two pages."

But Chamorro did not say he had removed the section on "Selective Use of Violence for Propaganda Effects," which calls for the "neutralizing" of political officials.

After he made his objections known, Chamorro said, several boxes of the manual were picked up from his offices by U.S. personnel and he did not know where they were taken.

Several members of Congress have expressed concern that by advocating the "selective use of violence" to "neutralize" Nicaraguan government officials, the book is endorsing political assassination.

Sen. Daniel Patrick Moynihan (D-N.Y.), vice chairman of the Senate Select Intelligence Committee, yesterday complained that the administration has "so far told the press more about the manual . . . than they have told the Intelligence committees."

He said a staff briefing promised Monday by the CIA is "a wholly inadequate response," and demanded answers to questions on the document's origins, funding, and relationship to laws requiring that Congress be kept informed of all intelligence activity.

Reps. George Miller (D-Calif.) and Thomas J. Downey (D-N.Y.) called on the attorney general to appoint an independent counsel, or special prosecutor, to probe whether the CIA violated criminal laws barring murder of foreign officials and conspiracies to damage the property of foreign governments.

The White House has announced investigations into the matter.

Several Americans and Nicaraguans directly involved with the "secret war" against the Sandinista government privately expressed reservations about the tendency toward extreme measures, which last became the center of major political debate after the CIA mining of Nicaragua's harbors earlier this year. But Chamarro's doubts have been more public than most.

As long as four months ago, Chamorro, a former Jesuit and philosophy professor, described the contents of the manual as "stupid or criminal," but he did not make a complete copy available. He said then that he was concerned some complete texts had fallen into the hands of the Sandinistas and would be used for propaganda against his group.

Speaking about the author of the manual, Chamorro said in an earlier interview, "Some of these people do not have a clear moral philosophy of what we can do. If you do this, then what is the difference between you and the Mafia?"

Chamorro said he is still a member of the seven-person directorate of the Nicaraguan Democratic Force, which has received most of the CIA's funding to fight the Sandinistas, but added that his objections to U.S. influence on the organization are not necessarily shared by his colleagues. Since early summer, Chamorro said, he has found himself increasingly isolated from the other members of the organization and from the CIA.

Chamorro said he still believes in the need to rid his country of the Sandinistas but he said of the kind of thinking behind the manual, "I now realize the similarity with Vietnam. The American who was helping us, he was just giving us the spirit, the situation ethic of Vietnam."