Aides to D.C. Mayor Marion Barry have uncovered extensive personal diaries -- as many as 10 detailed, handwritten volumes -- kept by Robert Robinson, the former administrative officer whose handling of the mayor's spending records is a central issue in a grand jury investigation of Barry's expenses.

The documents, stacked in several boxes behind a fourth floor District Building kitchenette, were shown on Wednesday to FBI agents, who are reviewing them. Sources said that in addition to the journals, the boxes include Robinson's personal papers and copies of official contracting and financial documents, some of which were seized by the FBI.

It was unclear yesterday whether the documents contain actual financial records that could provide new details of Barry's controversial ceremonial fund, although sources said the boxes did not appear to contain records from 1982 to 1984.

City officials have said records from that period were destroyed before a grand jury began investigating whether any money from the $17,500 annual fund was used for personal expenses of Barry or his family.

Robinson's lawyer said yesterday that his client had been trying unsuccessfully for months to retrieve the documents from the city. City officials said that they were aware of the boxes but did not know their contents until a clerk looked in them on Friday.

Meanwhile, Annette Samuels, Barry's former press secretary who is on academic leave, confirmed yesterday that in 1985 she borrowed $500 in cash from the fund to buy an airline ticket for her son, who had run out of money in Europe. Samuels said she repaid Robinson in cash two weeks later.

Samuels is the second high-ranking Barry official who has acknowledged use of the official fund for personal reasons.

Anita Bonds, a key Barry political adviser, said that Robinson lent her $1,850 in cash in 1984, which she repaid four days later. Bonds said recently she was unaware that the money had come from the fund. Bonds and Samuels testified recently before the grand jury about their loans.

Barry has said it is possible the fund was used to pay $1,500 of a fur coat bill for his wife but, if so, without his knowledge.

Barry has said Robinson paid the bill, but said the aide told him the money came from Robinson's private savings account. Barry said he repaid Robinson in cash.

City financial managers said it is improper to use an official fund to provide loans to government employes, even if they reimburse the fund.

Although it is too early to tell how important the records may prove to be to investigators, the existence of detailed entries of Robinson's activities may suggest the former aide was more organized than Barry and other aides previously have implied.

Last year, when Barry first revealed that records of thousands of dollars in his personal travel expenses were in disarray, Robinson was depicted by Barry and other top officials as a well-intentioned administrator who was simply in over his head and unable to keep proper records. In recent weeks, Barry has publicly criticized Robinson for doing "all kind of crazy things," such as paying for the fur and keeping poor records of his expenses.

"The existence of these records shows that the whole statement about Rob not keeping records is {untrue}," said one former city official.

The diaries, which are green cloth-bound accounting ledgers dating to the early 1980s, also could provide investigators with new insights into how the inner circle of Barry's office conducted business. Robinson, a supporter since Barry's first campaign for mayor in 1978, was known as a "Mr. Fixit" who could cut bureaucratic corners to get things done, according to several officials.

Robinson's friends said he had so many day-to-day projects and administrative emergencies to handle that he had to keep records just to remember them all.

City officials and Robinson's lawyer, Samuel J. Buffone, gave differing interpretations of how the Robinson files have been handled. Buffone said officials were aware of the files because his client "over a period of months" has asked for them, and has been told they had been "impounded."

District officials gave a different account, saying it was a mystery to them why Robinson had not retrieved his personal files after he moved out of the fourth floor suite of rooms used by the Office of Intergovernmental Relations.

According to knowledgeable officials, Robinson's files had remained in his office until recently when a new staff member packed them up in boxes and moved them to an adjacent kitchenette.

"Nobody wanted to go in there {Robinson's office} and nobody looked at them because they thought they were Rob's personal files," an official said. Officials said the nature of the files became apparent only when Alfonza Fitzgerald, a clerk who had worked with Robinson, looked through the files in search of a Haines directory.

Officials said aides to Dwight S. Cropp, director of the office and Robinson's longtime supervisor and friend, told Corporation Counsel Frederick D. Cooke Jr. that the records seemed to be more than personal papers. The papers were moved to Cooke's office for the weekend.

On Wednesday, according to sources, the mayor's controller, George Thomas, placed the records in a vacant fourth-floor office to allow FBI agents to review them. The records were locked in the room early Wednesday night, but aides were startled to discover later that night that the doors were wide open and painters were at work in the room. Cooke and Special Counsel Eric T. Washington, informed of the security breach, rushed from their third-floor offices, placed the files on a handcart and wheeled them back to the corporation counsel's offices, according to sources.