Liverpool are said to have written to the referee body PGMOL regarding their recent game against Aston Villa.
The Reds, who drew the game 1-1 despite a late Roberto Firmino goal, were frustrated by the match officials in the contest.
One incident saw Tyrone Mings aim a chest high challenge at Cody Gakpo.
However, he was only given a yellow card by the referee, and the VAR did not decide it was worthy of a red card either.
Another incident involved an offside goal that Gakpo scored, which Liverpool felt should have stood.
Regarding the goal, Virgil Van Dijk was flummoxed by it all, saying: I didn't understand what was going on.
I asked (fourth official) Michael Oliver on the side and apparently it was a question if the Villa player deliberately headed it back and I have no idea if he did, yes or no.
I've no idea. I think it would be good if next season we can hear what they discuss, everyone around it, and be transparent.
For them to explain with you guys, coming here, that's what happened in Holland, why not over here?"