Walter Byers, executive director of the National Collegiate Athletic Association, has responded to charges that NCAA staff members may have tried to discourage cooperation with a congressional subcommittee investigation of NCAA practices by urging member institutions to report any such improprieties directly to the subcommittee chairman.

In a Mailgram sent to some 100 schools involved in infractions investigations since 1970, the period being probed by the House Subcommittee on Oversight and Investigations, Byers suggested that any suspicion of improper conduct by the NCAA staff be communicated confidentially to subcommittee chairman John E. Moss (D. Calif.).

Moss raised the question of NCAA interference in s sternly-worded letter to Byers last week, after the subcommittee voted to subpoena files on infractions investigations. The NCAA had refused to supply the files voluntarily, citing an agreement of confidentiality with its member institutions.

Moss accused Byers of showing "bad faith and a reckless disregard for the seriousness of this investigation." He charged that a Nov. 8 letter from Byers "virtually encourages member institutions not to cooperate with this investigations to lobby members of Congress against the investigations."

The Moss letter continued: "You are free, of course, to contact any member of Congress. It will have no effect on this Subcommittee. But let me suggest that in my 25 years in Congress, I have rarely seen an investigation so warmly embraced by my fellow members. I am confident that any such clumsy efforts to frustrate our investigation will go unrewarded.

"Finally, Mr. Byers, I have received disturbing reports that officials at member institutions have received telephone calls from NCAA staff about this congressional investigation. Those calls have been perceived, rightly or wrongly, as veiled threats of reprisal.

"Lest you inadvertently fail to appreciate the gravity of implications of sucha cts, please be advised that . . . it is a felony punishable by fine and imprisonment to endeavor to influence, intimidate, or impede any witness before a congressional committee.

"Let me emphasize that I will not hesitate to refer evidence of any such act to the Department of Justice for prosecution. Accordingly, by copy of this letter, I am today asking all affected member institutions of the NCAA to report to the Subcommittee immediately any such incidents."

The subcommittee's subpoena was served Tuesday morning at NCAA headquarters in Shawnee Mission, Kan., requesting the controversial files - which include raw date of NCAA investigations of recruiting and other infractions - by Nov. 28. NCAA officials said yesterday they would comply and were readying the subpoenaed documents.

The Moss subcommittee announced Oct. 4 it was investigating alleged abuses by the NCAA. Among the questions it is studying are whether the NCAA is violating any antitrust laws; whether its investigative methods provide for due process; and whether penalties meted out to institutions, athletes and coaches found to have violate; d NCAA regulations are fair and equitable.

"The NCAA possesses the unbridled authority to ruin the careers of athletes, destroy coaches'professions and deal staggering blows to the athletic reputations of its member institutions," said Rep. Jim Santini (D. Nev.), a member of the subcommittee.

He requested the inquiry after the NCAA placed the University of Nevada - Las Vegas basketball team on probation for two years and ordered suspension of coach Jerry Tarkanian for alleged violations.

The NCAA voluntarily supplied documents requested by the Subcommittee detailing penalties it has imposed for violations since 1970, but it refused to provide other case reports without permission of the schools involved.

In a Nov. 16 letter to Moss, turning down the Subcommittee's blanket request for the files, Byers cited the NCAA's agreement with its member institutions to keep confidential all information supplied in infractions investigations.

"In those instances in which permission is granted (by member institutions), we . . . will again request that the Subcommittee treat the information in confidence, notwithstanding the refusal to honor any such request expressed by the Subcommittee staff in a meeting with our legal counsel last month," the Byers letter added.

Moss retorted angrily in his letter the following day, announcing the subpoena.

"Quite simply, neither the NCAA nor any other association can, by agreement among themselves, take away the investigatory powers of the Congress . . ."

Moss went on to chastise Byers for implying that turning over the files to the subcommittee would compromise their confidentiality.

"You grossly mischaracterize representations of subcommittee staff on the subject of confidentiality," Moss wrote, adding, "I rest secure in the long and unblemished record of this Subcommittee in handling sensitive documents.

"At the same time," Moss letter continued, "you should be aware that the Subcommittee may always authorize disclosure of evidence it deems to be in the public interest . . ."

This oft-repeated proviso, plus what Byers has called "serious questions concerning the ability of congressional committees to maintain the confidentiality that often is promised," had some NCAA officials apprehensive as they prepared to ship their files to Washington.