THE $668,800 that D.C. businessman Jeffrey E. Thompson directed to an illegal “shadow campaign” that helped elect Mayor Vincent C. Gray (D) in 2010 has been the focus of abundant attention. Less notice has been paid to another $50,000 in questionable expenditures by Mr. Thompson, which allegedly benefited a close friend and a close relative of Mr. Gray. These payments, too, must be cause for concern, particularly since some of them allegedly came after the mayor took office.

In court documents filed in connection with Mr. Thompson’s guilty plea to two felonies, federal prosecutors said that after the September Democratic primary, Mr. Thompson paid $10,000 to cover campaign expenses (cash to people who had worked in support of Mr. Gray) promised by the mayor’s relative. The request, according to prosecutors, came from Vernon Hawkins, the mayor’s long-time friend, who pleaded guilty for his part in running the shadow campaign. After Mr. Gray was in office, Mr. Thompson is alleged by prosecutors to have paid more than $40,000 “for home improvements, employment, and other items for the benefit of a close personal friend” of the mayor. Payment was made, according to prosecutors, through Jeanne Clarke Harris, another friend of Mr. Gray’s who has pleaded guilty to charges related to the shadow campaign.

The recipients were not named in the court filings, in an interview with Mr. Gray’s attorney, but WUSA-TV9’s Bruce Johnson identified them as Carlos Gray, the mayor’s son, and Linda Greene, the mayor’s ex-girlfriend. The mayor’s attorney, Robert Bennett, told Mr. Johnson — and reiterated to us — that the mayor had no involvement with and no knowledge of either of these arrangements. He pointed out that Ms. Greene had her own independent relationship with Ms. Harris. Carlos Gray, his attorney and Ms. Greene did not return our calls for comment.

Mr. Gray’s defense that he knew nothing about these payments echoes his claims that he was unaware of the misdeeds of Ms. Harris, Mr. Hawkins, Mr. Thompson and others to get him elected four years ago. Federal prosecutors say the mayor had detailed knowledge about the illegal fundraising operation. In asking voters to give him a second term, Mr. Gray needs to provide more answers. Has he talked to his son since the allegations surfaced? Can he say categorically there is no substance to the charge? Did he, as prosecutors allege, thank Mr. Thompson for getting work for the friend?

When gifts or favors are given to friends and family of elected officials, voters have a right to ask questions.