Congressional investigators "probably" could break into a private home and take papers out of a locked drawer if they committed the burglary to get information for a legislative purpose, the federal government told the Supreme Court yesterday.

Arguing on behalf of congressional investigators who obtained copies of papers ordered sequestered by a federal court, Deputy Solicitor General Frank H. Easterbrook told the court that the Constitution provides absolute immunity to senators, representatives and their staffs "for any speech or debate in either House," saying that "they shall not be questioned in any other place."

"An immunity that would protect only when no wrong was alleged to have been committed would be no immunity at all," Easterbrook argued.

When asked by Justice Potter Steward whether the constitutional protection would extend to a burglary of a private home, Easterbrook agreed that it "probably" would but added that he didn't find the notion of such a break-in "intuitively appealing."

Easterbrook's adversary, Morton Stavis, counsel for Alan and Margaret McSurely, agreed that the grant of immunity is absolute, but argued that it applies only to such legislative activities as voting, making speeches and issuing committee reports. It does not mean burglaries or free-roaming field investigations by congressional sleuths who "snoop around or break the law," he told the justices.

In the McSurely case, the central issue is whether the "speech and debate" clause protected the actions of the late Sen. John L. McClellan (D-Ark.), chairman in the 1960s of the permanent subcommittee on investigations, and three subcommittee staff members, two of them now dead.

The case dates back to 1967, when McClellan's subcommittee was investigating urban rioting. At the time, the McSurelys were organizers for the Southern Conference Educational Fund Inc. in Pike County, Ky. In addition, Alan McSurely was affiliated with two unincorporated associations, the National Conference of New Politics and Vietnam Summer.

Acting under a Kentucky sedition law, Commonwealth Attorney Thomas B. Ratliff, then a candidate for higher state office, obtained search and arrest warrants, raided the couple's home, and seized a large volume of books, pamphlets and other materials, including love letters.

But a panel of three federal judges agreed with the couple that the sedition law was unconstitutional on its face, enjoined prosecution and ordered prosecutor Ratliff to hold the seized materials in safekeeping.

After that, Ratliff announced that he would make the materials available to congressional subcommittees. The McClellan unit dispatched the late John Brick to look at them. Then, in a motel room, a county detective gave Brick photocopies of 234 documents that he took back to Washington.

In the 11 years of litigation that followed, which included a conviction of the McSurelys for contempt of Congress that the courts overturned, the U.S. Court of Appeals for the District of Columbia ruled in December 1976 that the McSurelys could sue McClellan (now his estate) and the subcommittee aides for damages because "speech and debate" didn't protect violations of their privacy.

Yesterday, for purposes of argument, the government's Easterbrook assumed that the taking of the 234 documents violated the Fourth Amendment to the Constitution. But, he said, the conduct still was immunized because it was part of an investigation made for a legislative purpose.

Upping the ante from his earlier hypothetical question, Justice Stewart asked if the "speech or debate" clause would protect a burglary in which investigators "killed a couple of people," albeit for a legislative purpose.

An admittedly troubled Easterbrook acknowledged that it probably would.

Easterbrook said the immunity for pursuit of information is far-reaching and cannot be restricted to situations where formal subpoenas are authorized. But he qualified his answer by adding that it is "at least conceivable" that the unchallenged right of Congress to ask for information doesn't encompass a right "to take it by force."

The McSurely papers were "handed over," not seized, he stressed.

Chief Justice Warren E. Burger suggested that the answer to questions such as Stewart's is that burglaries and the like aren't part of the McSurely case.

Disagreeing, Stewart said the questions were justified because Easterbrook was arguing that a legislative purpose allows congressional investigators to do almost anything.

Similarly, Justice Byron R. White summed up the government position to be that "deliberate theft" is immune, if the purpose is to legislate.

Justice John Paul Stevens told Easterbrook that if he is right, Congress could "send a policeman to break in and take things by force."

Easterbrook, who acknowledged "admitted difficulties" with the case, said he assumed Congress would not do things illegally or by force because that would be "wrong."