World Rugby pull England vs. Ireland assistant Marius van der Westhuizen

Marius van der Westhuizen will run the line on Saturday but refereed an England training session on Tuesday. Laurence Griffiths/Getty Images

World Rugby have pulled Marius van der Westhuizen as assistant referee for Ireland's Six Nations Grand Slam clash with England on Saturday, replacing the South African with Nigel Owens.

The Rugby Football Union and coach Eddie Jones came under fire this week after van der Westhuizen officiated a training match at England's Pennyhill Park base on Tuesday.

In a statement released Thursday evening the world governing body stated that van der Westhuizen "should not have been involved given that he was a member of the match official team".

Earlier Irish head coach Joe Schmidt had defended the official's integrity but described the situation as a "surprise".

Schmidt said of the session: "I am sure in retrospect people are probably thinking it may not have been the best thing to do.

"I know Marius, I would have no hesitation in standing by his integrity. I don't think it will affect his decision making and we would still have faith in him as an official on Saturday."

At his media conference Jones had deflected blame for any conflict of interest in the direction of the governing body.

"There's no advantage [gained], we went through World Rugby, which is the proper channel," England head coach Eddie Jones said when quizzed on the decision to bring van der Westhuizen into camp.

"You're asking the wrong person. You should be asking World Rugby. We went through World Rugby and asked for a Southern Hemisphere referee to help us with our breakdown and that's who they offered."

World Rugby have clarified that in the future a member from the high-performance match official panel will be available to attend training sessions, as long as the member is not part of the match official team officiating that team within that Test window.