PHOENIX (AP) -- The University of Arizona has reported a possible NCAA recruiting violation by men's basketball coach Lute Olson.

The veteran coach calls it "an unfortunate and regrettable error."

Athletic director Jim Livengood says Olson had sent a letter to basketball boosters asking for a donation to Jim Storey's Arizona Cactus Classic basketball tournament.

The event was held last May at Arizona's McKale Center. NCAA rules prohibit institutional representatives or boosters from arranging financial assistance for potential recruits.

Livengood says the alleged violation did not involve a specific athlete.

Livengood adds the NCAA is investigating and that university officials would have no further comment until the process is concluded.