The independent counsel investigating former housing and urban development secretary Samuel R. Pierce Jr. has hinted that he may issue a sweeping subpoena to a House subcommittee for a number of documents it discovered in its 14-month investigation of the Reagan administration scandal.

Independent counsel Arlin Adams has been seeking the documents for several weeks, and on July 18 wrote a letter to subcommittee Chairman Tom Lantos (D-Calif.) urging him to "resolve the impasse" over his efforts to obtain the panel's documents.

Congressional aides said a subpoena for the panel's documents could impede any future congressional inquiries into the HUD scandal, raising questions about the separation of powers between the legislature and the judiciary. Congressional committees typically seek to steer clear of criminal investigations and zealously guard their independence from proceedings in either the executive or judicial branches.

Members of the Lantos's subcommittee on employment and housing, however, frequently have encouraged prosecutors to examine the evidence of "widespread abuses, influence-peddling, blatant favoritism, monumental waste and gross mismanagement" the panel said was rampant at HUD during Pierce's eight-year tenure.

Congressional aides said yesterday that some of the subcommittee's actions, including a 27-page letter the panel sent last week to Adams, had not been cleared by Rep. John Conyers Jr. (D-Mich.), chairman of the parent Government Operations Committee, and that Conyers had expressed concerns to Lantos over the prosecutor's demands.

"Mr. Conyers is aware of the situation. He is in control of the situation and hopes it can be worked out," said Julian Epstein, the committee staff director.

Stuart E. Weisberg, the subcommittee staff director, said, "Historically there always has been haggling between independent prosecutors and committees. It's not something out of the ordinary or unusual."

Weisberg said, however, that the subcommittee has no intention of releasing any information it received on a confidential basis. The subcommittee, which has ended its hearings, is in the process of writing its final report.

Adams, through a spokeswoman, declined to comment, citing "the ongoing investigation."

One congressional aide familiar with the dispute between Adams and the subcommittee said that Conyers feared the subcommittee had moved too swiftly in its investigation and may have compromised the ability of Congress to delve back into the HUD debacle.

The subcommittee's investigation was underway before Adams, a former federal appeals court judge from Philadelphia, was named in March to investigate Pierce's conduct.

Since then, the subcommittee has supplied him with copies of numerous documents it released during its more than 120 hours of hearings. Last week, it attached about 50 documents to the 27-page letter it sent Adams, urging him to expand his investigation. The letter was signed by all subcommittee members.

In his July 18 letter, Adams mentioned that a subpoena might be issued for unreleased documents, although he added "we would not contemplate issuing a subpoena without your acquiescence. . . . "

In a list that Adams attached to the letter, he indicated that he wanted documents from five areas:

All documents "referred to" during the subcommittee's 27 hearings.

All of Pierce's papers, including "all documents that contain any notation, message, note, comment, or other mark of whatever form generated by Pierce."

All documents concerning the activities of Deborah Gore Dean, the Pierce aide who was portrayed during hearings as a key figure in HUD operations.

All documents concerning former assistant HUD secretary Thomas T. Demery, an official who was in charge of housing programs at the department during part of Pierce's tenure.

All documents concerning the controversial renovation of a hoisery mill in Durham, N.C., a project HUD funded despite strong objections from the department's professional staff. Pierce denied pressing for approval of the project, but his testimony was contradicted by a senior HUD official.