Accused South Korean agent Tongsun Park has told persons close to him that he gave former Rep. Otto E. Passman (D-La.) more than $100,000 in cash over the years, but federal investigators apparently have been unable to substantiate the claims.

James Hamilton, Passman's attorney, denied a report in yesterday's New York Times that said Passman received $190,000 in 1972 from Park and a Park aide.

Park is said to have told Justice Department investigators last year, before he left the United States for London and then Seoul, that he never gave Passman any funds. But he told others privately that he made more cash payments to Passman, at least $100,000 than to any other member of Congress.

Park has indicted in August on charges he conspired with Korean Central Intelligence Agency officials to bribe mambers of Congress.

Passman, now 77 and in failing health, was a power in Congress for years because of his position as chairman of the House Appropriations subcommittee which held a virtual veto over foreign aid. He took a special interest in Food for Peace funding, which was a source of millions of dollars in commissions on rice sales for Tongsun Park.

Park often accompanied Passman on trips to the Far East.

Justice Department officials refused to comment yesterday on the Times story. But others familiar with the investigation said that possible criminal cases against a handful of congressmen, including Passman, have been held up because Park has not been available as a witness.

Because Park was known to make payments in cash with no witnesses present, his testimony would be needed in a trial against Passman or others.