Liverpool on Sunday said a botched VAR decision that cost them a goal in their 2-1 defeat at Tottenham resulted in "sporting integrity being undermined".
Referees' body the PGMOL admitted a "significant human error" had meant Luis Diaz's strike, when Saturday's game was level at 0-0, was not awarded by a VAR review after being flagged offside.
PGMOL chief Howard Webb also reached out to apologise to Liverpool on Saturday evening.
The match officials at fault for the mistake were stood down from duty for the rest of the Premier League weekend.
"Liverpool Football Club acknowledges PGMOL's admission of their failures last night. It is clear that the correct application of the laws of the game did not occur, resulting in sporting integrity being undermined," read a statement.
"We fully accept the pressures that match officials work under but these pressures are supposed to be alleviated, not exacerbated, by the existence and implementation of VAR.
"It is therefore unsatisfactory that sufficient time was not afforded to allow the correct decision to be made and that there was no subsequent intervention."
Liverpool added that they will now explore their options "given the clear need for escalation and resolution."
Victory at the Tottenham Hotspur Stadium would have taken Jurgen Klopp's men to the top of the Premier League table.
However, they had a mountain to climb after just 26 minutes when Curtis Jones was shown a straight red card after the VAR officials did intervene to instruct an on-field review for his challenge on Yves Bissouma.
The visitors should still have taken the lead when Diaz's strike found the far corner and replays showed he had been played onside by Cristian Romero.
Liverpool's fury was compounded when Spurs took the lead moments later through Son Heung-min.
The 10 men fought back to level at 1-1 before half-time through Cody Gakpo.
But Liverpool were then reduced to nine men for the final 20 minutes when Diogo Jota was sent-off for a second bookable offence.
The Reds still nearly held out for a remarkable point until Joel Matip's 96th-minute own goal handed Spurs victory.
"I never saw a game like this with the most unfair circumstances, crazy decisions," said Klopp.
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