The brother of a man charged in the fatal bombing of an Alabama abortion clinic intentionally cut off his left hand with a circular saw to send a message to government agents searching for his brother, the authorities said today.

The Federal Bureau of Investigation said it had received a videotape that the brother, Daniel Rudolph, had made while he was amputating his hand at his home in North Charleston, S.C. The videotape includes an undisclosed message to Federal agents who have mounted a nationwide manhunt for the man charged, Eric Robert Rudolph, 31, the officials said.

Daniel Rudolph amputated the hand on Sunday and drove himself to the nearby Summerville Medical Center. An ambulance crew was sent to retrieve the hand, and Mr. Rudolph was transferred to Roper Hospital, where the hand was surgically reattached, officials said.

Daniel Rudolph has been interviewed by the F.B.I. as part of a manhunt for his brother, but a bureau spokesman said he was not under investigation in the fatal Jan. 29 attack on the New Woman All Women Health Care Clinic in Birmingham, Ala. An off-duty policeman was killed in the explosion and a nurse was seriously injured.