The First U.S. Circuit Court of Appeals yesterday issued an interim order permitting a Boston federal grand jury to resume investigation of the release of the Pentagon Papers.

The probe had been halted on October 29 pending a ruling on a contention by Senator Mike Gravel (D-Alaska) that attempts to subpoena two of his associates infringed upon his legislative immunity.

The court ruled that neither Gravel nor his aides and staff members could be called to testify before the grand jury, pending the court's final decision on Gravel's claims.

The decision rebuffs the attempts of government attorneys to subpoena Dr. Leonard Rodberg, an aide to Gravel, and Howard Webber, head of the MIT Press, whom Gravel reportedly contacted about publication of the Pentagon Papers.

The court also prohibited the grand jury from questioning witnesses about Gravel's acquisition use, or publication of the Papers.

Rodberg said yesterday that he was glad the court had recognized Gravel's claim.

"It looks as if they are taking seriously that Senator Gravel, his associates, and I are legitimately entitled to legislative immunity," Rodberg said.

He added that this ruling, in addition to a court order one month ago prohibiting evidence obtained through wiretapping, means there are "very few people" left to testify.

Gravel's lawyers had requested the right to preview any questions that Rodberg or Webber might be asked by the grand jury. They contended that Gravel's legislative immunity, providing that he may not be called to account for any act performed as senator, might be endangered through the questioning of his associates.

Government attorneys opposed Gravel's request on the grounds that it would cause the grand jury investigation to bog down in "a nightmare of litigation" and denied that the questioning would put Gravel's immunity in jeopardy.

The temporary order allows the grand jury hearings to continue until the court makes a final decision on whether or not Gravel and his associates will be required to testify