BLOOMINGTON, Ind. (AP) _ Bob Knight feels betrayed by the release of a videotape showing him grabbing former player Neil Reed's neck during basketball practice, his son says.

Pat Knight, a former Indiana player and now an assistant at Indiana, said the tape was taken by former assistant Ron Felling, who was fired in December. Felling could not be reached for comment.

``Here's a guy like Felling who steals that tape. He's going around telling people that he's got it,'' Pat Knight said.

``Thirteen years of loyalty to someone, and he's pulling that kind of stuff. It makes me sick,'' the younger Knight told The Indianapolis Star.

The tape surfaced Tuesday night when it was aired by CNN/Sports Illustrated. Indiana officials, investigating a claim by Reed that Knight choked him during a practice in 1997, said they knew of the tape's existence but did not know who had it or who supplied it to the Atlanta-based news network.

``We have known of the possibility of a tape existing for several weeks and have tried diligently to get the tape back and we've been unsuccessful,'' university vice president Christopher Simpson said Thursday. ``We still believe it is our property and would like it back.''

Simpson said he did not know why Felling was fired or whether it was he who gave it to CNN.

However, Indiana associate athletics director Steve Downing said earlier this week that Felling approached him at an IU baseball game last month and told him he had the 21-minute tape in his possession and was holding it ``as his trump card.''

Simpson said he had not talked to Downing, who did not return telephone calls from The Associated Press. Bob Knight also could not be reached for comment.