D.C. Mayor Anthony A. Williams is having his attorney look into whether there is a potential conflict of interest involving Williams's wife, a board member in a nonprofit group seeking $3.7 million in city funds to construct a tennis and learning center in Southeast Washington.

Diane Simmons Williams joined the D.C. Recreation Wish List Committee this year at the invitation of Cora Masters Barry, the wife of former mayor Marion Barry. The nonprofit group initially planned to use private funds to build the tennis center, but last week Williams (D) said he would use the surplus from four finished projects to help complete the $5.1 million project.

The city's sudden involvement in a project that involves the mayor's wife could present a conflict of interest. Asked about the matter in Denver, where he is attending the U.S. Conference of Mayors, Williams said, "We look at all these conflicts all the time. . . . I know we have someone looking at this now.

"And if there's any questions [of improprieties], then she will leave. This is something we're going to look at very dispassionately."

Peggy Armstrong, the mayor's spokeswoman, said Williams asked the family's personal attorney, Robert M. Krasne, of Williams & Connolly, to research the issue.

At a hearing last night, D.C. Council members focused their questions on whether other projects would be shortchanged by the amount spent on the tennis center.

Robert P. Newman, the city's interim recreation director, and Othello Mahone, interim director of the Department of Housing and Community Development, spent two hours trying to reassure council members that no other project has been put on hold to finance the center.

"I'm not going to sit here and say there are not other needs, but this one is on our doorstep and it's up at bat now," Newman said, adding that a developer and an architectural design already have been selected.

Some city officials have expressed concern that the tennis center would involve taking $2 million from the long-awaited development of an abandoned D.C. National Guard post in Southeast Washington. But Newman and Mahone said city officials are negotiating with a private developer to take over that project, at the former Camp Simms.

The Recreation Wish List Committee, founded more than four years ago, plans to build the Southeast Tennis and Learning Center at Sixth Street and Mississippi Avenue SE. The facility will include a computer lab and tutors on staff.

Most of the half dozen council members who participated in last night's hearing lauded the concept of the center. Cora Barry sat in the council chambers accepting hugs and encouragement from about two dozen supporters.

Diane Williams, an accountant at the Greater Washington Urban League, has had limited involvement with civic issues. After Anthony Williams in April called the tennis and learning center one of his favorite nonprofit projects, he was asked about his wife's involvement with the Wish List committee.

At the time, the mayor said he did not think Diane Williams served on the committee, although by then she was a board member. Before she became a member, her only official role in city business appeared to be as treasurer of the mayor's constituency services fund, which has nearly $150,000 to be used in emergency situations for needy residents.

Diane Williams was out of town and could not be reached for comment, Armstrong said.

Staff writer Michael H. Cottman contributed to this report from Denver.