Howard Brooks, a campaign consultant to Mayor Vincent C. Gray, was a no-show at a D.C. Council committee hearing on hiring practices Thursday.

Council member Mary Cheh (D-Ward 3) said Brooks, whose son was hired and later resigned from the administration, contacted the committee through his attorney.

The attorney said Brooks would not appear because he was “in the midst” of being interviewed by the U.S. attorney’s office and would appear after that process ended, Cheh said.

Cheh said she expected Lorraine Green, chairman of Gray’s campaign and transition, to testify Monday, along with Judy Banks, former interim director of the Department of Human Resources.

But she said she has not been able to solidify a schedule. Cheh said she will begin using subpoena power to call witnesses. “It doesn’t mean they are unwilling,” Cheh said.

Sulaimon Brown, a fired city employee and former mayoral candidate, has alleged that Brooks gave him payments during the primary to continue verbal attacks on then-Mayor Adrian M. Fenty. The Washington Post has not been able to independently verify payments.