McCullough was facing misconduct charges because of alleged racist language towards Armitage during and after their European Cup group 5 matches on December 9 and 15 last year.

McCullough came before the ERC in Dublin on Wednesday and a subsequent statement from the tournament organisers said: "The disciplinary committee accordingly determined that the misconduct complaints against Mr McCullough should not be upheld."

A statement released by Ulster reacting to the decision said: "Both Ulster Rugby and Matt McCullough welcome the verdict of the Independent Disciplinary Committee.

"Throughout the period leading up to the hearing, Ulster Rugby and Matt McCullough strenuously denied that anything said was, or was intended to be, of a racially derogatory nature.

"However, the need for ERC to fully investigate any claims of racism is recognised and, while the period leading up to the verdict has been difficult for Matt and his family, the hearing has provided an opportunity for Matt to clear his name."