Washington (CNN) - Mayor Vincent Gray knew in January 2012 that members of his staff had not properly reported funds raised for his 2010 campaign, according to a source close to a federal investigation into his campaign funding.

When Jeanne Clarke Harris, a public relations consultant, told Gray in a meeting that she had not reported all the expenditures from the campaign, the mayor instructed her to report them right away, the source said. Harris pleaded guilty this week to helping orchestrate a secret campaign on Gray's behalf.