THE BOARD of directors of the Washington Metropolitan Area Transit Authority has retained a prominent law firm to conduct an independent investigation into a development proposal involving Ward 1 D.C. Council member and former Metro board member Jim Graham (D).

It’s a welcome, albeit overdue, sign that the authority is taking seriously the allegations that have been raised about Mr. Graham’s conduct and is committed to finding the answers.

Cadwalader, Wickersham & Taft, an international law firm with extensive experience in internal investigations, was selected by the board’s audit and investigations committee to examine decisions involving the efforts of Banneker Ventures from 2008 to 2010 to develop Metro-owned land on Florida Avenue NW. The allegations about Mr. Graham center on whether he improperly tried to get the firm, which had won an open competition, to withdraw from the Metro deal by offering to support the separate bid of a Banneker principal for the D.C. government’s lucrative lottery contract. Banneker officials allege their development ultimately failed because of continued obstructions by Mr. Graham. Mr. Graham has denied any wrongdoing; he says that Banneker failed because of inherent weaknesses in its plans and operations.

In a Jan. 20 report that examined numerous aspects of the city’s controversial handling of its lottery business, the D.C. inspector general found insufficient evidence to warrant further inquiry. But the IG said that Mr. Graham’s actions raised questions about his impartiality and independence that could undermine public confidence in government integrity. E-mails that this page obtained detail the concern by members of the group seeking the D.C. lottery contract that Mr. Graham was making inappropriate, if not illegal, demands. City officials were aware of the allegations and in possession of the troubling e-mails in 2008; Metro officials were alerted in 2010, but neither entity bothered to investigate. Passing the buck between the two jurisdictions left unanswered whether one of its leading officials tried to use his influence to punish perceived political enemies and steer business to a favored firm.

Mr. Graham has said that his interest in suggesting to Banneker that it try to include another firm in the project was based solely on the belief it would result in a better development. “On all matters, there has been no allegation of any crime, nor any personal financial benefit to me,” Mr. Graham e-mailed to us on Friday.

Metro promised that its review, expected to take several months, will be thorough. It will be led by firm partner Bradley J. Bondi, experienced in conducting investigations for boards, public companies and other organizations. Metro’s announcement Friday came the same week in which a federal judge ruled that Mr. Graham, along with Mayor Vincent C. Gray (D), must give depositions in the wrongful-termination case of former contract officer Eric Payne, who claims that political shenanigans affected the council’s handling of the lottery contract. Mr. Graham said of the order that he be deposed: “I welcome the opportunity to clear the air.”