In a tweet early Friday, University of Hawaii football coach Nick Rolovich accused Oregon State of sending recruiting material to at least one of his players last month.

It is against NCAA rules for a school to contact a player who has signed a National Letter of Intent with another school.

Rolovich tweeted to his 12,000-plus followers photos of recruiting material, including an invitation to OSU’s spring game on April 28, that were allegedly sent from the Beavers to UH players. The materials were mailed to the Queen Liliuokalani Center for Student Services on the Manoa campuses.

The recipients’ names were redacted in the tweet. One of the brochures boasts of the OSU staff’s collective 203 years of coaching experience.

Rolovich tweeted: “My apologies for our players not being able to attend your Spring game. Ours was the same day, bad timing. Quick question, the 203 years of coaching, none of you realized you couldn’t actively recruit another school’s players? Sent to campus?#leakydam #sloppybeavers.”

Rolovich texted to the Honolulu Star-Advertiser on Friday: “Sorry, I can’t talk right now.” UH athletic director David Matlin was traveling and unavailable for comment.

In a statement OSU said, “Oregon State Athletics and head coach Jonathan Smith became aware of unintentional mailings directed at a University of Hawaii student-athlete this morning. We are committed to following NCAA rules and are looking into this matter fully.”

According to the statement, the contact was categorized as “unintentional.” After NBC Sports Network reported that OSU “accidentally” sent the material, Rolovich tweeted: “‘Accidentally,’ Thank goodness. I feel so much better.”

There have been recent connections between the two football programs. In January 2016, Jake Cookus resigned as UH’s special teams coordinator to move to Oregon because of a family illness. Cookus joined OSU as quality control analyst. This past December, he was promoted to special teams coach. Also in December, receivers coach Kefense Hynson and defensive coordinator Legi Suiaunoa resigned at UH to accept assistant coaching jobs at Oregon State. In January, offensive lineman Brandon Kipper transferred from UH to OSU.