CHAPEL HILL, N.C. (AP) — John Blake has resigned his position on North Carolina's football staff, effective immediately, school officials said Sunday night.

Blake, who was in his fourth season working with Butch Davis, said in a statement issued by the school that he stepped down because "my presence has become a distraction" to the university.

"Consequently, I have determined that it is in the best interests of my family, the university community at large, and the football program for me to step down from my position as associate head football coach," Blake said.

The NCAA has spent much of the summer investigating whether defensive lineman Marvin Austin and receiver Greg Little received improper benefits from agents.

That probe has since expanded to include possible academic misconduct, and 13 players did not travel to Atlanta for Saturday night's game against LSU. Also drawing the NCAA's interest is Blake's longtime friendship with California–based agent Gary Wichard.

"Coach Blake had indicated to me in previous conversations that he would step down if he felt his presence with the football program would become a distraction," athletic director Dick Baddour said. "I know the young men he coached are tremendously disappointed, but Coach Davis and his staff will help and support them as the season moves forward."

Blake will be paid $74,500, an approximation of the salary he would have received had he finished the season, and it will be paid by football revenues, the school said in the statement. His contract, which includes an annual base salary of $240,000, would have expired June 30, 2011, the school said.