Mayor Walter E. Washington may be called to testify as a witness in the trial of former D.C. human resources director Joseph P. Yeldell and real estate developer Dominic F. Antonelli Jr., according to federal court documents filed this week.

Yeldell and Antonelli are scheduled to go on trial Monday in U.S. District Court on charges alleging that they conspired in the corrupt awarding of a $5.6 million city government lease. Both men have pleaded innocent to the charges.

The mayor, a longtime political associate of Yeldell, was named both by federal prosecutors and by defense lawyers as a possible witness in the trial. A subpoena requiring the mayor to be available for possible testimony has been issued, according to reliable sources.

Whether the mayor will, in fact, be required to testify either for the prosecution or the defense is uncertain. A spokesman for the mayor referred all questions about the trial to the U.S. attorney's office, which also declined to comment. The mayor is known to have appeared before the grand jury that indicted Yeldell and Antonelli earlier this year.

The mayor's name appeared in a list of 125 potential witnesses filed in court Monday by federal prosecutors. It also appeared in a list of 126 names of possible witnesses submitted Monday by defense lawyers.