A Republican congressional aide has told the FBI that Paul Corbin, a political consultant with old-line Kennedy connections, claimed last spring that he had obtained President Carter's briefing papers for the 1980 presidential debate and had given them to Ronald Reagan's campaign manager, William J. Casey.

Tim Wyngaard, executive director of the House Republican Policy Committee, has told FBI investigators that Corbin made that claim to him in a telephone conversation last April--about six weeks before the debate papers controversy became public.

Casey emphatically denied in an interview this week that he had received any Carter debate briefing material from Corbin or anyone else. "I never knew this material was in the campaign," said Casey, who is the director of the CIA. ". . . It's totally false," Casey added.

Casey said confusion about Corbin may have arisen because Corbin did provide Casey with a six-page memo from a New York lawyer outlining possible statements Reagan might make in the October, 1980, debate with Carter in Cleveland.

Casey said he is a friend of Corbin's and authorized the Reagan-Bush Committee to pay Corbin $2,860 for expenses for what Casey said was routine campaign work in Florida in the fall of 1980.

Officials involved in the FBI investigation of how Carter campaign papers came into the possession of the Reagan campaign view Wyngaard's version of the Corbin conversation as potentially significant because it is the first evidence that someone voiced knowledge about the Carter debate papers before the episode was first mentioned in the media. One investigative source cautioned, however, that its accuracy may turn out to be "unprovable."

Corbin declined to respond to reporters' inquiries. But associates of his said he denies ever obtaining the Carter briefing papers or making such a claim to Wyngaard.

Corbin's alleged claim to the congressional aide has been known to the White House since last June, and has figured in the dispute between Casey and White House chief of staff James A. Baker III over which top Reagan campaign official first received the Carter briefing papers. Baker says he got the Carter papers from Casey; Casey says he never saw them.

On June 24, Corbin's alleged claim was relayed to Baker by Wyngaard's boss, Republican Policy Committee Chairman Dick Cheney (R-Wyo.). Baker then discussed it with Casey.

After his discussion with Baker, Casey told a middle-level White House official who is also a confidant that he was considering changing his original denial that he had never received the Carter debate documents, according to one reliable account.

This Casey confidant said that Casey told him he recalled receiving something from Corbin during the campaign and could not recall if it was the voluminous Carter debate papers.

Casey has given this account of how he went about determining that his denial should stand:

As the White House began its own internal inquiry into the matter in June, Casey told White House counsel Fred F. Fielding that Corbin could have provided him with some Carter debate papers.

Casey called Charles Bartlett, a former Washington columnist who had introduced Casey and Corbin, to see if Bartlett had any idea of what Corbin had provided the Reagan campaign. Bartlett reportedly did not. At that point Casey tried to find Corbin, and finally reached him by telephone on June 29 while Corbin was vacationing in Aruba.

In that call--according to accounts made public afterward by Casey and Corbin--Corbin said the only information or material he had provided to Casey was a few pages of material from New York attorney Adam Walinsky, former top adviser to the late Sen. Robert F. Kennedy (D-N.Y.).

After the talk with Corbin, and after Casey found the Walinsky material, Casey said he was convinced that he had fully and accurately stated his recollection.

Though the Walinsky material previously has been referred to in newspaper accounts as a speech, it is a memo recommending points Reagan might use in debating Carter, including an attack on what Walinsky called "President's Carter's many disasters." Unlike the 1,000-page Carter debate papers, it is a slim, six-page memo that is addressed to Corbin and begins "Dear Paul."

Investigative sources said Corbin also had sent the Walinsky memo to Baker, who was running the debate preparation group in the Reagan campaign. Baker also knew Corbin. Bartlett has said he had introduced them.

Baker declined to comment this week about the matter.

Corbin, a controversial figure in Democratic politics with longstanding ties to the Kennedys, apparently circulated widely during the 1980 presidential campaign. On Oct. 24, 1980, according to Federal Election Commission records, the Reagan-Bush Committee paid Corbin $1,500 for what was described only as "field trip" and on Nov. 3 it paid Corbin $1,360 for "professional services and phone."

Corbin had begun the 1980 campaign as a volunteer in Sen. Edward M. Kennedy's effort to win the Democratic presidential nomination from President Carter.

After Carter won renomination, Corbin was among those who urged his old friend, former Wisconsin govenor Patrick J. Lucey, to run as vice president on the independent ticket of John B. Anderson and advised him on occasion during the fall campaign, Lucey said in an interview.

Wyngaard said that Corbin said he was angry at Carter because Carter had declined to present Mrs. Robert F. Kennedy with a medallion that had been established by Congress in honor of her late husband.

Wyngaard said Corbin was proud of the fact that in 1981 Reagan presented the medallion to Mrs. Kennedy, in a ceremony attended by the entire Kennedy family, including Sen. Edward Kennedy, and friends, including Corbin. Other Corbin associates confirmed that he felt this way.

Corbin did not respond to repeated queries. His attorney, Herbert J. Miller, said this week that his client has done nothing wrong and would not comment.

Cheney and Wyngaard told The Washington Post that they had been interviewed by the FBI. They confirmed the accuracy of the version that was learned by reporters, but would not discuss the details.

Wyngaard's version is that he specifically recalls Corbin taking credit for having obtained Carter's debate briefing book and delivering it to Casey. Wyngaard also recalls that Corbin mentioned separately, and during another part of the telephone conversation, that he had arranged for Adam Walinsky to write a speech for Reagan.

Wyngaard has maintained that Corbin also said, in talking about the Carter debate book, that he knew that a Pennsylvania consultant who served as a debate coach for Reagan had found the Carter briefing book useful.

Wyngaard, who said Corbin was an old family friend, told the FBI he could place the date of the telephone conversation because he was given Corbin's unlisted office number on the day after Easter, which was April 3. He placed the call no more than a couple of weeks later.

The first public mention of the debate briefing book episode occurred on June 9, when The New York Times and The Washington Post published brief accounts from a book on the Reagan White House by Laurence Barrett. On June 23, newspapers reported that senior Reagan administration officials had sent letters to the House Civil Service subcommittee of Rep. Donald J. Albosta (D-Mich.), which had begun to investigate the matter.

That led Wyngaard to discuss Corbin's claim with House Republican Policy Committee Chairman Cheney in a conversation on the House floor. Cheney told FBI investigators that he passed the word along to Baker at the White House.

Cheney's telephone logs show that he placed a call to Baker on Friday, June 24, and that the call was completed later that day.

Baker then discussed the matter with Casey in a meeting during that weekend of June 25-26. The two men were trying to formulate a public explanation to resolve their conflicting letters to the Albosta subcommittee.