The “pro bono” audit of the D.C. tax office by a high-profile law firm is growing less free by the day.

In a letter dated Tuesday to D.C. Council leadership, firm WilmerHale said the city will be on the hook for up to $200,000 in out-of-pocket expenses, from photocopying to bike messengers. WilmerHale was enlisted by the council to lead the investigation into the largest corruption scandal in District government history.