The Iran-contra committees will question additional witnesses in coming weeks in an attempt to settle some of the contradictions and unanswered questions developed by 11 weeks of public and closed-door hearings, Rep. Lee H. Hamilton (D-Ind.), chairman of the House select committee, said yesterday.

"Despite the impression that the committees' investigation ended with the close of public hearings," Hamilton told reporters at a breakfast yesterday, there are "a lot of depositions to be taken, . . . there are some leads we need to follow up on." Among those to be recalled, according to congressional sources, are Rodney B. McDaniel, the former National Security Council staff member who took notes at President Reagan's daily intelligence briefings in 1986; Michael Ledeen, a former consultant to the NSC who played a key role in the 1985 Israeli shipments of U.S.-made arms to Iran; and James R. Radzimski, who maintained NSC files of sensitive documents and reportedly has testified about seeing at least one other document similar to the so-called diversion memo which outlined an arms shipment to Iran and contained mention of spending some of the proceeds to help the Nicaraguan rebels.

The committees also will call other witnesses who have not been questioned before, but sources refused to name them or say how many there would be.

Hamilton said continuation of the inquiry was needed because with "almost every single witness there are questions we don't know the answer to, but probably should know." As he had during last Monday's closing statement, the House chairman noted that the panels had not "ruled out additional public hearings if the evidence warrants it," but added there was limited time left to the investigators.

The House and Senate panels are scheduled to report to their respective chambers in October.

Yesterday, the committees concluded their currently scheduled hearings when the last of three top Central Intelligence Agency officials appeared in a closed session.

Over the past three days, the committees have questioned Duane (Dewey) Clarridge, the agency's counterterrorism chief; CIA Central American Task Force chief Alan Fiers; and Clair George, the CIA's chief of covert operations. Each of the three had been interviewed before, but their earlier testimony was put into question by statements made by North and other witnesses during their appearances.

Clarridge, a close friend of North, coordinated the controversial November 1985 air shipment of HAWK missiles by Israel to Iran; he maintained to the panels that he believed at the time that the cargo was oil-drilling equipment.

Fiers and George were said by North and the CIA's Costa Rican station chief, who uses the pseudonym of Tomas Castillo, to have known of and approved of North's and Castillo's activities on behalf of the contras at a time it was prohibited by law.

Hamilton, at the breakfast, said the closed-door testimony on Tuesday and Wednesday had not shed further light on the role played by the late CIA Director William J. Casey.

He added, however, that he now believes Casey played "very much a central role" in the Iran-contra affair, a conclusion he came to after listening to testimony that included North's repeated mention of Casey as an adviser on his covert activities in support of the contras, including the diversion of funds from the Iranian arms proceeds to support the rebels.

Asked to comment on Vice President Bush's assertion in The Washington Post yesterday that the hearings have placed him beyond criticism in the Iran-contra affair, Hamilton reiterated that the committees' work is not yet complete.

"So long as that's the status of it, I'm not going to make any comment with regard to Vice President Bush, or any other person, that has any finality to it," Hamilton said.

"We have very little evidence of the vice president's involvement. So far as I know that's the status of things. But it is also a tentative judgment on my part."