An investigative news report on the federal witness protection program was broadcast last night after a day-long judicial struggle in which an appeals court ovrturned a lower court order barring the broadcast.

WCVB-TV of Needham aired the first of a five-part series on the U.S. Justice Department program on its 6 p.m. news after state Appeals Court Judge John M. Greaney lifted a lower court restraining order just an hour before the broadcast.

Greaney agreed with station attorney's who argued during a half-hour hearing that the earlier order by Norfolk Superior Cour Judge Fancis Keating, violated First Amendment freedom of the press guarntees.

The rest of the series, "Witness for Hire," will be broadcast on the next four Mondays, also on the WCVB-TV 6 p.m news.

In allowing the show to go on the air, Greaney rejected prosecution arguments the broadcast would generate publicity harmful to the state's case in the murder trial of Myles J. Connor Jr., 37, who is charged with the 1975 slayings of two Boston women.

Earlier in the day, Keating ruled the series could interfere with the trial because of its discussion of the use of paid criminal informants by law enforcement officials.

A paid witness has been used in the Connor case.

Greaney threw out the earlier ruling and said jurors have "a marvelous capacity to overlook and forget about these things."

Greaney said other steps could be taken to minimize the impact of the report on potential jurors. He suggested defense or porsecution lawyers might ask for a delay in the trial or for a change of location.

Keating is scheduled to preside at Connor's trial begining Oct. 14.

Connor was charged in the stabbing deaths of Susan C. Webster and Karen T. Spinney, both 18, on Feb. 21, 1975.