An FBI report prepared when D.C. Superior Court Judge Robert H. Campbell was nominated for his judgeship in 1972 contained numerous allegations that Campbell adjusted traffic tickets while he worked in the D.C. corporation counsel's office, according to law enforcement sources who have seen the report.

The sources said the report included allegations that Campbell received cases of liquor and other gifts in return for throwing out traffic tickets in the city prosecutor's office before they reached a judge.

Campbell was nevertheless appointed to the bench by President Nixon and confirmed by the Senate after being strongly supported by a number of local and Capitol Hill politicians.

Campbell is now under investigation by a federal grand jury here, which has been presented evidence of an alleged pattern of favoritism in Campbell's lenient handling of hundreds of overweight truck tickets for a large Washington area construction firm.

He is also being investigated for possible judicial misconduct by the city's judicial tenure commission for his alleged lenient dispositions of tickets for the construction firm. Excavation Construction Inc., and other firms with large fleets of vehicles.

Investigators are reviewing allegations this leniency contrasts with strict fines and sentences Campbell has imposed on many individual traffic violators who have come before him in court.

According to law enforcement and other sources, Campbell also was the subject of earlier grand jury investigation here into the allegations that he received gifts for adjusting tickets while he worked in the corporation counsel's office. That investigation was dropped, however, because of the relatively small monetary value of the alleged gifts and the reluctance of the FBI to become involved in a small investigation of a local judge.

The current, much more extensive investigation, which involves hundreds of thousands of dollars of traffic tickets, began with an allegation that a local policeman was fixing tickets. Investigators who studied computer printouts of dispositions of traffic tickets here eventually found a pattern of widespread leniency in the handling of tickets for fleet vehicles.

The investigations then focused on a period between October 1975 and May 1977 when Campbell repeatedly suspended fines of $100 to $300 each on hundreds of overweight trucks tickets issued to Excavation Construction Inc., according to records. Excavation Construction is run by local parking and contruction executive John Lyon.

Campbell, who earlier denied any improprieties or favoritism in his handling of case while serving in Superior Court's traffic branch, has not responded to reporters' telephone calls to his chambers and his home during the past two days.

Allegations of ticket adjusting have dogged Campbell since his days as a prosecutor in the corporation counsel's office which he joined in 1954, later rising to assistant chief of the law enforcement division (in 1963) and chief of the division (in 1967).

A year before being named chief of the law enforcement division, Campbell was accused by critics - including members of his own staff - of being too willing to make adjustments for various violations - particularly traffic tickets.

At that time, it was reported that a random check of two days of traffic court records showed that nine of 30 traffic charges dismissed were dropped by Campbell. Campbell told a reporter however that he never adjusted a violation without good cause and said the records themselves do "not reveal the true meaning of why something was done." Various factors, including the availability of witnesses, the nature of the charge, or errors in the way the ticket was issued could account for his decision not to prosecute a case, he said.

Campbell served as chief of the law enforcement division for five years until 1972, when he was appointed to his 15-year-term on the Superior Court bench by President Nixon. Lawyers who worked for Campbell while he was chief of law enforcement expressed conflicting opinions yesterday about the way he administered the office.

Campbell "ran the office well," said Charles H. Schultze, a former assistant corporation counsel who is now in private practice.Schultze, like others interviewed, recalled the pressures that came with running an understaffed prosecutor's office handling a large volume of traffic, housing and licensing violations.

When it came to traffic tickets, employes said, police officers by the dozens and streams of citizens flooded the office with requests that their tickets be adjusted for a wide variety of reasons.

Some lawyers have contended that tickets were frequently adjusted in the corporation counsel's office, especially for police officers and other court employes who argued that they had been cited for traffic violations while on official business.

Last April, an assistant corporation counsel who was fired from his job after a crackdown on ticket adjustments claimed that "since time immemorial every assistant in the Law Enforcement Division has been allowed, and indeed urged, to adjust (traffic) citations against fellow employes."

At the time, D.C. Corporation Counsel John R. Risher Jr. acknowledged there had been a problem with ticket adjustments.

Campbell, by his own account, has spent much of his time as a Superior Court judge presiding over the confusion and massive caseload in the city's traffic court. Campbell has said that he has spent 22 months in traffic court over the past five years and handled more than 100,000 cases.

It is the judge's conduct in that courtroom that has brought him the harshest criticism from lawyers who claim he has been tough with individual defendants but lenient with large corporations.