UEFA president Michel Platini has said that he wants conversations between football officials to be recorded.
The Frenchman's comments come after a controversial goal in the first leg of the Champions League semi-final between Bayern Munich and Barcelona.
Thomas Muller appeared to block Jordi Alba, preventing him from challenging Arjen Robben, who went on to score Bayern's third goal of the match.
"I don't believe nobody saw the foul. Why was nothing said?" BBC Sport quotes Platini as saying.
"I have asked the general secretary to record conversations between officials in matches involving five officials."
Having five officials (one referee, two on the touchline and two new assistants near the goal) was first tested in the Europa League before it was introduced to the elite Champions League this season, and Platini is wondering how fouls are still being missed.
"There were three international standard referees involved and none of them saw it. Something is not right," added the 57-year-old.
"If the referee were on his own, he wouldn't have seen it, and two might not have seen it either but, between three, they have to see it."
Bayern went on to win the tie 7-0 on aggregate to set up an all-German final against Borussia Dortmund at Wembley on May 25.
