Sources close to "Star Search" tell TMZ that when David was a contestant back in the day, Jeff's behavior was so bad, he was eventually barred from the lot! The guards actually had a picture of Jeff's mug hanging in the guard shack in case he tried sneaking in.
We're also told the father of the year harassed Tiffany Evans, his "Star Search" rival, lurking outside her practices, even trying to coerce her into drinking milk before a show to ruin her voice. She didn't listen (obviously) and went on to win.
Sources also tell us Daddy Dearest sometimes screamed at his son and has even withheld water during rehearsals, even bringing his son to tears.
As far as "Idol" goes, we hear papa's wrath is still in full blossom. That might explain why Jeff, who normally sits in the audience, was replaced by other family members last week.