Mayor Walter E. Washington and top officials of his 1974 election campaign-related equipment rental supplies and legal expenses that were not reported as required by law.

The payments, in the form of three Riggs National Bank cashier's checks, were made May 14, 1976, for the 6-month rental of Xenor copying machine used in the mayor's campaign, paper for the machine and legal fees for a law suit brought by the Xerox Corp. for collection of the overdue bill.

A local businessman, John B. Jvey, in whose name the Xerox machine was rented, was informed by his lawyer in a May 14 letter that unnamed "friends or associates of Mayor Washington's 1974 campaign" had paid the $5,400 dept to settle the suit. But the lawyer, R. Kenneth Mundy, said yesterday he did not know who those persons were.

Mayor Washington said in an interview that he paid $4,900 of the amount from "my own personal funds." The remaininf $500, the mayor said, was paid by William Lucy, the campaign chairman.

The mayor refused, however, to further identify the source of the "personal funds." He also said he did not know why the money had been paid in three cashier's check that bore only the signature of Riggs National Bank official.

The mayor said that attorney James L. Hudson, who was vice chairman of the mayor's campaign, had handled the details of the payments. Hudson, after refusing on several occasions during the past week to return a reporter's phone calls or to be interviewed in his office, said yesterday he would not discuss the payments because they were "a private matter."

Charles B. Duncan, the treasurer of the campaign, said the expenditures had not been reported to the D.C. Board of Elections and Ethics because campaign officials considered then to have never been authorized by the mayor or his registered campaign committee, the Committee for Washington, an had no proof that they were directly related to the campaign.

Knowledgeable campaign sources said, however, that the Xerox costs resulted from a little-known alternative campaign on behalf of the mayor run by Maurice A. (Al: Lockhart, a 60-year-old former D.C. policeman and acquaintance of the mayor. It was Lockhart who signed the Xerox rental contract on behalf of Ivey on Aug. 21, 1974.

Lockhart's activity, the sources said, came at a time when managers of the mayor's election drive were worried about shoring up what some considered to be a faltering campaign organization under the eadership of campaign coordinator John Dean. Many of the mayor's closest advisers doubted Dean's ability, sources said.

The Dean-run campaign had originally been budgeted to spend as much as $400,000, sources said, but four weeks before the crucial Sept, 10 primary, Congress imposed a $200,000 spending limit. One source said the use of Ivey's name in the Xerox rental contract was a way of allowing Lockhart to carry out the activity without its costs being reported as required.

Sources have previously told The Post that concern with violating the spending limits also was a reason that $1,400 in secret cash payments were allegedly used to pay the salaries of campaign workers but not reported as required by law.

The Post reported Dec. 23 that, according to knowledgeable sources, city administrator Julian Dugas, the mayor's longtime friend and closet political confidant, gave the money - some of it in $100 bills - to Dean who in turn used the cash to pay workers' salaries.

Dugas has denied giving Dean the money or having any involvement to the campaign. Dean has refused to comment on the financing of the campaign. Mayor Washington has denied any knowledge of secret cash used in his campaign.

Sources involved in the campaign portary Lockhart, a free-lance consultant and public relations man from Oak Bluffs, Mass., as a boastful man who frequently bragged of his involvement in various national political campaigns.

Mayor Washington, Lucy and Duncan acknowledge that Lockhart performed some "volunteer work" for the campaign, but all three deny that he was ever authorized to act on behalf of the mayor's election drive.

Nevertheless, well-placed campaign sources said Lockhart beleived that he had a commitment first from Lucy and later from Dean to carry out various campaign activities whose coasts would be met by the campaign comittee.

Among those activities, the sources said, were production of an unknown number of 45-page, Xeroxed election day directories listing such information as the names of key campaign staffers, telephone numbers, names of drivers,polling places and even "comfort stations," and "churches working for Washington."

The sources said Lockhart worked out of a rented three-room office suite at 1010 Vermont Ave., NW, right around the corner from the office in which Ivey's limousine service, John B. Ivey Associates, was headquartered. The offices was two floors above a telephone bank that the Washington for mayor campaign had already established in the offices of the D.C. Democratic Central Committee.

The sources said Lockhart deployed at least three drivers equipped with car telephones to improve communications among various, campaign offices. He also for a short time ran a single-bus shuttle service among the campaign offices, according to the sources.

Sources said Lockhart's activities were part of a $10,000 plan that Lockhart cutlined to Lucy on Aug. 13 during a lengthy meeting in Lucy's office. The sources said the mayor had directed that Lockhart be taken to Lucy, but the mayor denied giving any such directions.

Lucy acknowledged having the lengthy meeting with Lockhart. He said Lockhart told him he was coming on the basis of a "long-standing friendship with the mayor's family."

"He talked about the fact that there were certain things in his observation that needed doing and what he'd like to do is work on these things," Lucy said. "But he wasn't to make a move," Lucy said, until the activities were cleared by campaign coordinator John Dean.

"There's great disagreement as to whether or not he was given authority," Lucy said. "Dean said he never game him any authority."

Knowledgeable, campaign sources said that Lockhart felt he had received an initial go-ahead from Lucy on the day following the meeting and a subsequent authorization from Dean later, on the condition that payment would not be made until after the primary election.

But the sources said Dean was extremely concerned about, Lockhart's activity, partly because the discussion between Lockhart and Lucy had taken place on a day that Dean was out of town. The sources said Dean was frustrated in his efforts to find out who had suddenly authorized Lockhart's activites, and later came to feel that higher-ups in the campaign hierarchy had made some "commitment."

One source said Dean felt the commitment to Lockhart was evidence of a lack of faith in his own ability."They were trying an end-run to overlay all of Dean's activities," the source said. Dean would not comment on the matter.

The role of the mayor and his top aides in Lockhart's activities is almost as unclear as the disputed authorization of those activites.

Knowledgeable sources said that the mayor and city administrator Dugas personally talked with Lockhart about a possible role in the campaign on several occasions.

Sources said the mayor and Dugas also met with Lockhart on Aug. 13 at the mayor's office in the District Building. It was the mayor who later sent Lockhart across the street to the campaign office to meet with Dean. When the mayor learned that Dean was not in town, the sources said, he directed Lockhart to be taken to Lucy.

The mayor acknowledged meeting in his office with Lockhart on one occasion, but said it was not Aug. 13 and they met for "a very few minutes." Dugas was present at the meetings, the mayor said.

Sources also said that Lockhart had presented a bill for "$5,000 to $6,000" to the mayor and Dugas after the campaign, but the mayor said he never received such a bill. Dugas said through a spokesman that he "knows" Lockhart, but Duags refused to discuss any other involvement he might, have had with Lockhart.

The mayor said he agreed to pay the money to settle the Xerox claim because he felt it was a "nuisance suit" and an innocent party, Ivey, might be harmed if the payment were not made.

"It would have taken time and taken me away from my office and would have incurred added expenses." the mayor said. Other sources said the settlement came in the face of a threatened countersuit by Ivey, in whichthe mayor and top compaign offices would be named.