The special counsel of the Senate Ethics Committee, hired to investigate charges of impropriety against Sen. Edward W. Brooke (R-Mass.), resigned yesterday, charging that Brooke's lawyers had withheld information requested by the committee and altered some documents.

Brook responded within hours with a dramatic speech to a hushed Senate chamber, attacking the committee's counsel, Richard J. Wertheimer, and demanded an opportunity to confront him at once in a public meeting of the committee.

Brooke denied that information had been withheld, and said the only case of a document's being altered involved a bookeeper's mistaken entry that was later voluntarily corrected.

Sen. Adlai E. Stevenson (D-Ill.), chairman of the Ethics Committee, disagreed politely but firmly with Brooke in an address to the Senate just after Brooke's:

"The facts are that not all the documents requested in the course of this initial review have been turned over . . . The facts are that the distinguished senator from Massachusetts may not have within his possession and his knowledge the information on which to base his assertion that there have been no alterations to materials except the one he mentioned . . ."

Later, a lawyer for Brooke, Barry Levine, in effect acknowledged that some material requested by the committee had not been turned over. Levine said repeatedly in a news conference that "virtually all" the information the committee wanted has been provided. Asked why he continually used the qualifying word "virtually," Levine said there were "ongoing" requests for information which, he suggested, had not yet been satisfied.

Brooke clearly made a strong emotional impression on the 45 or so Senate members who were in the chamber debating the Humphrey-Hawkins bill when Brooke rose on a point of personal privilege to speak on the sudden resignation of Wertheimer.

It was a moment every senator could identify with: a colleague fighting a fierce reelection campaign, tainted by recurring charges of improper behavior, which he had seemed to be rebutting with some effect, suddenly struck between his political eyes by a lawyer's charge that his representatives had frustrated and deceived the Ethics Committee.

Brooke rose to the occasion with a forceful, eloquent speech. His experience during the last year hounded by allegations growing out of an acrimonious divorce and subsequent dispute over personal property, had been "a nightmare," Brooke told his colleagues.

"I pray to God that none of you go through what I have gone through," he added. Many of the senators present looked self-consciously at their hands, avoiding Brooke's eyes as he spoke from his back-row desk on the Republican side of the aisle. But some turned to face him directly, including Russell P. Long (D-La.) and Jacob K. Javits (R-N.Y.).

"My counsel told me that the counsel the Ethics Committee had retained [Wertheimer] was antagonistic . . . and saw the investigation as an adversary proceeding," Brooke told the Senate. He charged that Wertheimer took the inquiry far beyond the issues raised by accounts of Brooke's personal finances that grew out of his divorce, but said he always cooperated with the Ethics Committee by providing whatever information it asked for and more.

Brooke lambasted the press for its handling of his affairs and particularly The Boston Globe. "What's happening in this country?" he asked. "This kind of investigative reporting we're going through today, without looking at the facts or even wanting to look at the facts is wrong . . . and it's got to stop. And I'm not fighting the press . . . This is a dangerous precedent and I call it to the attention of my colleagues."

The substantive purpose of the speech was to challenge the Ethics Committee: I demand that the committee immediately hold a meeting," Brooke said, to give him an opportunity for a "face-to-face" confrontation with Wertheimer.

When Brooke sat down the minority leader, Howard H. Baker Jr. (R-Tenn), and several others rose to speak sympathetically. Then Stevenson arrived in the chamber and began a response to Brooke.

A large rumpled version of his namesake and late father, Stevenson rarely has the impact as an orator that was his father's hallmark. But he did yesterday. Calmly and carefully, he explained what an awful job it was to lead the Ethics Committee, but then he defended its work as the keeper of the Senate's morals.

"This is a very unpleasant occasion for me," Stevenson said, "because I have the greatest affection . . . and respect . . . for my colleague from Massachusetts."

Charles Morin, were responsible for trying to thwart the committee's inquiry. Levine denied this.

The lawyer also said there had been no alternations of any documents, as Wertheimer charged, save for one occasion when the Senator's office manager had noted in his records that a "return of capital" was actually a "loan,' 'a mistake she subsequently found and corrected.

But then Stevenson said, in effect, that information had been withheld, and documents had been altered. And he said that the vice chairman of the Ethics Committee. Sen. Harrison H. Schmitt (R-N.M.), had invited Brooke on Aug. 3 to appear before the committee at any time.

"It is not until tonight that I have received his (Brooke's) request for that meeting," Stevenson said.

When all that was said, Stevenson seemed to go out of his way to speak well of Brook: "Based on everything I know about him and feel in my bones about that man, he is an honorable man."

The implication of his remarks, and of Wertheimer's letter of resignation, was that Brooke's lawyers, Levine and TEXT OMMITTED FROM SOURCE