Michael A. Brown will have to wait three more months to learn the full consequences for his caught-on-camera bribe-taking. (U.S. Justice Department)

As the federal investigation into District political corruption expands to national dimensions, the sentencing of a former D.C. Council member has been delayed for more than three months to allow him to cooperate with authorities.

Michael A. Brown, who pleaded guilty to a bribery charge in June, had been set for an Oct. 3 sentencing. But with a deadline for pre-sentencing filings looming, prosecutors on Wednesday asked that the proceedings be delayed at least until Dec. 16.

U.S. District Judge Robert L. Wilkins agreed Friday to reset Brown’s sentencing to Jan. 16.

Prosecutors explained in a court filing that they have “recently identified evidence of additional suspect conduct in the ongoing criminal investigation in which the defendant is cooperating.” The delay, they added, would allow them to investigate the evidence and determine whether Brown could assist them in that investigation, as he has agreed to do under his plea agreement.

Brown’s acceptance of $55,000 in bribes is not directly related to the ongoing investigation that centers on businessman Jeffrey E. Thompson — a probe whose scope has expanded, it was disclosed in court this week, to include the 2008 presidential campaign of Hillary Clinton.

But in plea documents, Brown admitted to taking a secret $20,000 payment from Thompson during his own 2008 campaign for an at-large D.C. Council seat. He was not charged in relation to that activity.

Brown, who faces 37 to 46 months in prison under federal guidelines, is the son of Ronald H. Brown, the late former commerce secretary under President Bill Clinton.

Brown’s attorney, Brian Heberlig, declined to comment on the extension, as did William Miller, a spokesman for U.S. Attorney Ronald C. Machen Jr.

Ann E. Marimow contributed to this post.