A top aide to D.C. Social Services Commissioner Audrey Rowe, responsible for dealing with homelessness and foster care, stopped working last December but continued to draw her $40,552 annual salary until she resigned May 23, according to city records.

Instead of working for the city, Ann Chinn, one of Rowe's three special assistants, spent "two to three days" each week at Artifactory, a clothing and art store near the D.C. Superior Court building. When interviewed at the store yesterday, Chinn said she does not get paid for helping customers and answering the telephone but is "just hanging around learning the business."

The situation is the latest in a series of management problems within the D.C. Social Services Commission, in which a top administrator resigned under fire last Friday and is being investigated for alleged overtime pay and contract abuses by the FBI, the General Accounting Office, the U.S. attorney's office and the city's inspector general.

Chinn's case is under active investigation, along with at least one other alleged instance in which a worker was kept on the payroll for some time but was absent from work, according to sources close to the investigation.

Chinn, 39, said she took vacation leave in January and February, but went to her city office one day a week during those months. Sick leave accounted for her other three months off the job, she said.

Chinn said her doctor wanted her to stop working in March 1985 because "the stress and strain" of her work was aggravating a medical condition, which Chinn declined to detail. She began taking sick leave in March of this year, she said, but was able to continue "observing" at the Artifactory because she often sits on a wooden stool there, she said.

"This is no strain," she said. "It's a matter of sitting here versus the level of work done as a special assistant."

Under D.C. personnel regulations, supervisors can grant extended sick leave only after receiving medical certification that an employe is incapacitated and cannot perform the job.

Rowe said she did not check to see if Chinn had a medical excuse before granting her extended sick leave. Rowe said she had heard that Chinn was "in and out of the Artifactory" and had visited the store, but did not find Chinn there.

After hearing that Chinn was "volunteering" and not being paid by the store, Rowe did not pursue the question of whether sick leave was being abused, she said. "That's where I left it," Rowe said. The owner of the Artifactory, Dominick Cardella, said yesterday he did not pay Chinn a salary.

Chinn's doctor, Dr. Peggy Scurry, submitted a letter justifying Chinn's sick leave on May 28, a week after Chinn's resignation from city government became effective. Scurry's nurse, Cheryl Edwards, said the May 28 disability certificate was the only medical excuse the doctor wrote for Chinn.

According to Rowe, Chinn's records show two medical excuses signed by Scurry, one covering the month of March and the May 28 letter.

In the letter, the doctor said Chinn had been under her care since April 21. The letter also recommended Chinn take medical leave beginning six weeks earlier, on March 1.

Neither Rowe nor Chinn could explain the discrepancy in dates, but Chinn said she had been seen by the doctor several months earlier. Rowe said the excuse for the month of March was signed with Scurry's name by her nurse. Scurry could not be reached for comment.

Chinn joined Rowe's staff in April 1980, shortly after Rowe became acting commissioner. Previously, Chinn had worked in the Department of Recreation.

Chinn said the sick leave "gave me time for my family and to do things I want to do." After 18 years in District government, Chinn said, she is interested in changing careers and opening an import business. "A couple of real estate agents are looking at places for me," she said.

City business was not affected by Chinn's absence, Rowe said. "Most of her duties were picked up by Miss Bonnie Politz," another aide, Rowe said. "Someone was always able to reach her Chinn at home. There wasn't any disruption of work product."

Rowe said Chinn told her last December that she had a medical condition that was affecting her work. "She wanted to leave government on a disability," Rowe explained.

"I told her to get me a medical excuse . I did not look at it."

Rowe's boss, David Rivers, director of the Department of Human Services, said he was told last week "there was a concern raised whether she Chinn was on sick leave." Rivers said he is investigating the case.