Former D.C. Council chairman Kwame Brown will appear before a judge next month to explain why he didn’t adhere to the conditions of his post-plea release. (NIKKI KAHN/THE WASHINGTON POST)

Neither a spokesman for the U.S. attorney’s office nor Brown’s attorney would discuss the nature of the violation.

But in an article that appeared in today’s Washington Post print edition but is not online, courts reporter Del Wilber revealed the reason: “Sources familiar with the matter say that [Brown] did not make at least one of the weekly calls to pre-trial supervision officials required under conditions of his release.”

After entering his guilty plea in June, Brown was released pending a number of conditions, including making the weekly calls to court authorities and staying within the D.C. area unless a judge says otherwise. Prosecutors can ask the judge to change his conditions of release if he violates those terms.

U.S. District Judge Richard J. Leon scheduled a hearing on the matter for Oct. 9.