A co-defendant in the assault and kidnap trial of Winnie Mandela said Tuesday that police threatened to kill him unless he implicated her in the abduction and beating of four black youths.

Four police officers had earlier said John Morgan, 61, signed a statement freely and voluntarily Feb. 23, 1989, linking Mandela to the crimes, and denied threatening or assaulting him.Morgan, during cross-examination in the Rand Supreme Court, said one of the officers, Lt. Dries de Klerk, told him if he protected Mandela, "they would kill me." Morgan has claimed the officers coerced a statement out of him with electric shocks and slaps to the face.

The officers have testified Morgan's statement was given of his own free will as, at the time, he had no intention of protecting Mrs. Mandela.