AUBURN, Ala. (AP) - Auburn coach Gene Chizik has declined to ``comment on speculation'' that the NCAA is investigating alleged improprieties involving the football program.

The Birmingham News reported Wednesday that NCAA investigators have interviewed at least one assistant coach and several players this week ahead of the Tigers' game against No. 2 Alabama.

The newspaper, citing an unnamed source, reported the investigation included but is not limited to the signing of running back Jovon Robinson, who was ruled ineligible amid allegations of academic improprieties.

Yahoo! Sports also reported Wednesday that the NCAA has been investigating potential wrongdoing involving Auburn recruits, players, coaches and others. That report says assistants Trooper Taylor and Curtis Luper haven't been allowed to recruit for several weeks.

Chizik has already been under fire during Auburn's 3-8 season.