Millicent D. West, the District’s homeland security director, resigned Tuesday, citing the ongoing federal investigation that led to a guilty plea by former D.C. Council member Harry Thomas Jr.

West said she stepped down, effective immediately, “to ensure the work of the agency can carry on without any distractions. . . . It’s in the best interest of the city and in the best interest of the agency.”

West, who described her departure as voluntary, is not accused of any wrongdoing, says a Washington Post report.

Thomas pleaded guilty last month to stealing more than $350,000 in public funds between April 2007 and August 2009 to pay for expensive cars, trips, clothes and meals.