(CNN) -- Auburn University quarterback Cam Newton is eligible to compete, the NCAA said Wednesday after probing an alleged pay-for-play scheme involving Mississippi State University.

Auburn declared Newton, a Heisman Trophy candidate, ineligible on Tuesday after the NCAA concluded Monday that a violation of amateurism rules had occurred, the organization said in a statement.

"When a school discovers an NCAA rules violation has occurred, it must declare the student-athlete ineligible and may request the student-athlete's eligibility be reinstated," the association said.

Reinstatement decisions are made by the NCAA national office staff. Newton was reinstated Wednesday without conditions, the NCAA said. The ruling means he is eligible to play in Saturday's Southeastern Conference championship game.

Newton's father, the Rev. Cecil Newton, and another person, referred to as an owner of a scouting service in the NCAA statement, tried to market Newton "as a part of a pay-for-play scenario in return for Newton's commitment to attend college and play football," the NCAA said. It has been widely reported that the school involved in the attempt was Mississippi State.

Auburn has limited Newton's father's access to its athletic program and Mississippi State has cut off relations with the other person, the NCAA said.

"In determining how a violation impacts a student-athlete's eligibility, we must consider the young person's responsibility," said Kevin Lennon, NCAA vice president for academic and membership affairs, in the statement. "Based on the information available to the reinstatement staff at this time, we do not have sufficient evidence that Cam Newton or anyone from Auburn was aware of this activity, which led to his reinstatement."

Auburn's football team is undefeated and ranked No. 1 in the BCS poll, thanks largely to Newton's running and passing, but pay-to-play allegations have dogged the team all season. Auburn faces South Carolina in the Southeastern Conference matchup on Saturday.

"The conduct of Cam Newton's father and the involved individual is unacceptable and has no place in the SEC or in intercollegiate athletics," said Mike Slive, Southeastern Conference commissioner. "The actions taken by Auburn University and Mississippi State University make it clear this behavior will not be tolerated in the SEC."

CNN's Jim Kavanagh contributed to this report