Marine Pfc. Robert Garwood lived as his captors' comrade in a Vietnamese prisoner of war camp, guarding fellow Americans, acting as an interpreter for the camp commander and participating in indoctrination sessions for American captives, a former POW testified today.

Army Chief Warrant Officer Francis G. Anton, of Fort Dix, N.J., led off a grand-jury-style hearing to determine if a court martial would be convened for Garwood, who returned to the United States in March after 14 years in Southeast Asia. Garwood, 33, of Greensburg, Ind., has been accused of deserting and collaborating with the Vietnamese enemy, both death penalty offenses. He has been stationed at this North Carolina base since his return.

Anton, 36, a pilot shot down and held prisoner by the Vietnamese for five years, cites a number of incidents in support of the charges against Garwood. His statements went unchallenged when the hearing recessed because procedural disagreements delayed cross-examiniation by Garwood's attorney until Wednesday.

Garwood, Anton said, lived on the fringes of their POW camp with interpreters and other North Vietnamese rather than with the American prisoners. He sometimes would accompany the Vietnamese as a guard on missions away from the camp and on one occasion served as the sole escort for prisoners sent to gather roots for food, Anton said.

"Even the guards that couldn't speak English called him Bobby," Anton testified.

Garwood often carried a "wallet or little pouch -- I can't remember which . . . It had a picture of Ho Chi Minh in it," Anton recalled.

Anton's anecdote-filled testimony provided a window on the life lived by the American prisoners, who number between 12 and 20 men.

The captives once were summoned for a series of indoctrination sessions on Vietnamese history and dogma conducted by a Vietnamese outsider known only as Mr. Ho, Anton said.

Ho, the camp commander, camp interpreter and Garwood, lined up in front of the prisoners, "in a little row," Anton said.

A disturbance erupted when one of the POWs was ordered to recite and muffed his lines, Anton said. Each of the instructors -- and Garwood -- then took turns berating the prisoner, he said.

Garwood told the prisoner Sgt. Richard Williams, "I spit on you" and threatened to punish him, Anton said.

Williams survived the POW camp but died after his return to the United States.

The "spit-on" incident forms the basis for one of five noncapital charges faced by Garwood, misconduct as a prisoner. On the lesser charges, Garwood could be dishonorably discharged and forced to forfeit more than $140,000 in back pay accrued since he himself was captured in September 1965.

Garwood, a high school dropout who joined the Marines at 17, showed no emotion as Anton described incidents from 1968 and 1969, when the two were together in a camp in South Vietnam.

With his hands folded in front of him at the defense table, Garwood glanced only occasionally at the witness stand while Anton testified in a calm voice.

Through his attorneys, Garwood has denied each of the accusations against him.