Auburn is back on the defensive amid allegations of wrongdoing dating to the 2010 national championship season.

Two reports surfaced this week accusing the athletic department of misdeeds ranging from covering up widespread use of synthetic marijuana among football players to grade-changing and illicit payments.

Auburn athletic director Jay Jacobs and other officials have disputed the findings in both reports, which painted a bleak picture of a department and football program that weathered an NCAA investigation into the recruitment of Heisman Trophy-winning quarterback Cam Newton through much of the title run.

Jacobs dismissed allegations made in an ESPN report that the school covered up use of synthetic marijuana as "baseless and inaccurate." Former football coach Gene Chizik said an earlier report on was "short on facts and logic."