A surgeon who testified during a hospital investigation in 1983 that Cmdr. Donal M. Billig was competent to handle heart surgery said yesterday that he did not tell the truth because he was "intimidated" by the chief of surgery and former commanding officer at Bethesda Naval Hospital.

Billig, the former head of cardiothoracic surgery at Bethesda Naval Hospital, has been charged with involuntary manslaughter in the deaths of five patients in 1983 and 1984.

Cmdr. Charles Lee, now head of the cardiothoracic division at the Bethesda hospital, described the 1983 investigation as a "whitewash" and said he was called as a witness to the investigation after complaining three times to Capt. Raymond Fletcher, who was then the chief of surgery.

During two of those talks, Lee said, Fletcher interrupted their conversation to call Commodore James J. Quinn, former commanding officer at Bethesda and then vice commander at the Naval Medical Command. Fletcher discussed the case with "J.J." and implied that "everything was under control," Lee said.

"The only reason I could deduce that he made (the phone calls) in my presence was he wanted to show me that this was the way Commodore Quinn wanted things to be done," Lee said.

Within the month, Lee told investigators from Bethesda in October 1983 that he believed Billig was improving as a heart surgeon. Yesterday, he was asked if that was true. "No . . . I felt the situation was being whitewashed and I was intimidated," Lee said.

Lee, who testified for eight hours yesterday, received a nonpunitive letter for his contradictory statements before the Bethesda investigators and then Navy investigators who investigated Billig a year later. Quinn and Fletcher have both since retired and received letters of censure.

Billig also has been charged with dereliction of duty based on 24 operations he conducted without proper supervision in 1983. His trial on those and the death charges entered its fourth week yesterday.

One death in 1984 received repeated criticism yesterday from Lee, who was appointed to Bethesda in 1983 and operated frequently with Billig. The death of Lois Parent, the wife of Marine Sgt. Maj. Maurice Parent, on Nov. 2, 1984, was caused by "avoidable errors," according to Lee, who operated that day and who recounted that Billig inadvertently gashed the woman's aorta.

Blood welled up in the heart and Billig reacted by "taking a step back. He was staring in a glaze. He looked like he was stunned," Lee said. Repairs were made but Billig later wanted to try to further bind the area, a step that Lee said yesterday was too risky for the patient.

Lee said Billig agreed not to try the repair and Lee, with Billig's permission, then left the operating room to take care of some personal papers. When he returned, Lee said, Billig had attempted another repair that failed. Parent bled to death, Lee said.

Lee's testimony followed similar statements by Lt. Cmdr. Phyllis Edwards, who assisted in the case. Late Friday, Edwards said Billig sliced the aorta and "froze" as blood "spurted for about 15 seconds" from the wound.

Anesthesiologist Lt. Cmdr. Joseph Coyle, also involved with the Parent case, said yesterday he did not believe Billig panicked after the mistake but that he did not "think that Dr. Billig had the experience, expertise or skills to handle problems when they occurred."