PHOENIX, NOV. 3 -- A state Supreme Court justice today temporarily halted a grand jury investigation of Arizona Gov. Evan Mecham's failure to report a $350,000 campaign loan.

Justice James Duke Cameron said the full court will hear arguments next Tuesday on whether state Attorney General Bob Corbin should be removed from the case.

The governor's attorney, Murray Miller, filed an appeal to the high court today, claiming that Corbin has a conflict of interest because he and the governor had a confidential attorney-client relationship.

The grand jury had been scheduled to begin its probe of the unreported loan at 9 a.m. today, and at least one subpoenaed witness, former Mecham aide Donna Carlson, arrived at the courthouse before the stay was issued. Mecham also had been among those subpoenaed to appear.

However, Assistant Attorney General Michael Cudahy said there was no confidential relationship on matters unrelated to Mecham's official duties. "Governor Mecham should not be able to forestall this grand jury investigation . . . by raising this collateral and bogus issue," Cudahy said.

The grand jury also was to consider whether the loan was tied to two gubernatorial appointments, and other undisclosed questions.

The Mecham Recall Committee, meanwhile, filed petitions that it said contained 388,988 signatures, far more than the 216,746 needed to force an election that could oust Mecham.

The recall campaign grew out of Mecham's cancellation of a holiday to honor the Rev. Martin Luther King Jr. and the governor's controversial public comments and appointments to state agencies.