The FBI is investigating allegations that the executive director of the D.C. Housing Finance Agency, Thomas M. Zuniga, charged personal expenses to the agency, according to sources familiar with the probe.

John M. Gibbons, a lawyer representing the housing agency, said yesterday it was his understanding that "if there were any personal charges, everything was promptly repaid" by Zuniga.

Zuniga's handling of agency funds also is the subject of an internal investigation by the agency's board of directors as well as a separate inquiry by the D.C. auditor, according to city officials.

Zuniga, through a spokeswoman, said yesterday that he was unaware of any FBI investigation and declined to comment on the matter.

The FBI investigation and the inquiries by the board and the auditor began after it was disclosed late last month that the agency's former office administrator, Kathleen I. Davis, had alleged possible misuse of agency funds by Zuniga. Davis' allegations came in a suit she filed Dec. 7 in D.C. Superior Court seeking reinstatement to her job and more than $1 million in damages for being fired.

Davis alleged in the suit that Zuniga used an agency American Express card issued in his name to pay for personal expenses, charged airline tickets for his children to the agency and authorized payment of agency funds without proper documentation.

The FBI is attempting to determine whether agency funds were used to pay for Zuniga's personal expenses, sources said.

Gibbons said the agency has denied all allegations of misuse of agency funds in a response to Davis' lawsuit filed last month.

Gibbons said he has interviewed agency employes and so far has found no substantiation of Davis' allegations. He said he has not yet reviewed Zuniga's credit card billings to the agency.

Davis said in an interview last month that she raised questions about the expenses to Zuniga in August and later detailed her allegations in a letter sent to Theresa L. Watson, head of the agency's board. Davis said that Zuniga fired her Oct. 30 after she gave him a copy of her letter.

Watson said yesterday that the board is reviewing expenses Zuniga charged to the agency. "We've gotten the bills and are checking them out," Watson said.

She said the agency has no plans to replace Zuniga, and she said she is unaware of any FBI investigation.

The Housing Finance Agency is a quasi-independent city agency run by an 11-member board made up of local banking executives, businessmen and government officials. The board makes policy decisions and day-to-day operations are carried out by a staff headed by Zuniga.

The agency sells millions of dollars in tax-exempt municipal bonds to finance housing projects, and provides low-interest loans designed primarily to help low- and moderate-income persons buy homes.

D.C. City Council member Charlene Drew Jarvis (D-Ward 4), who oversees the agency as chairwoman of the council's Housing and Economic Development Committee and who requested the auditor's investigation last month, expressed dissatisfaction yesterday with the agency's board and some of its recent decisions.

Jarvis said the agency, over her committee's objections, recently proceeded with a proposal to provide loans to some second-time home buyers. Jarvis said she believes the agency should restrict its loans to first-time buyers. Watson said the plan, which is awaiting approval by the U.S. Treasury Department, would allow aid to go to certain second-time buyers in targeted areas of the city in need of revitilization.