There is little appetite within the New Zealand Rugby Union for increasing television match officials' powers for next year's Super Rugby season.
The International Rugby Board's rugby committee will on Friday review two television match official (TMO) trials in South Africa's Currie Cup and the English Premiership, but NZRU boss Steve Tew said there were dangers involved in giving a TMO too much to do.
Match officials could become reluctant to make decisions, he said, and besides, viewing replays of incidents - such as the lead-up to tries - was time consuming.
"It's a bit of an unknown," Tew said. "It's like anything else, if you bring something in it has to add real value.
"It does come at an extra cost, it does take more time, so to add value to the game, does it discourage the referees from making intuitive calls on the paddock which is actually what we pay them to do? Does it improve the experience for the fans or the TV audience? All of those questions need to be weighed up.