Warren Gatland has challenged referees to stop New Zealand's off-the-ball "blocking" in the British and Irish Lions Test series.
Coach Gatland revealed the Lions have already raised the issue with officials ahead of the first Test against the All Blacks at Auckland's Eden Park on Saturday.
Gatland will meet first Test referee Jaco Peyper on Friday to discuss the Lions' concerns further, in a bid for a clean opening clash.
"The frustrating thing for us is the amount of blocking that's going on," Gatland said.
"It makes it difficult to complete attacking opportunities and situations.
"There is so much happening off the ball in terms of holding players or subtly holding players. We've raised it with the referees already.
"If you listen to the ref mic, they were talking about it constantly through the game. They gave a couple of penalties (in Saturday's 32-10 win over the Maori All Blacks) for blocking."
Gatland believes the Lions have been denied a number of try-scoring opportunities because of subtle blocking lines, especially against the Maori.
Asked if the Lions had been stymied, the 53-year-old said: "Absolutely, yeah. When you go back and look at the tapes and look at all the stuff off the ball, where someone's run a line or stopped someone getting through, some of it is very subtle."
The All Blacks have tried to call the Lions' bluff by suggesting Gatland's teams are one-dimensional - but the tourists' boss insisted he would not lose his nerve ahead of the Test series.