Liverpool manager Jurgen Klopp believes the referee was affected by an offside error made by his assistant in the 1-1 draw with West Ham United on Monday night.
Sadio Mane’s opening goal for the Reds was allowed despite James Milner being offside in the build-up. Michail Antonio equalised for the Hammers before half time, but Klopp insists referee Kevin Friend "did not want to open the gap any more" in the second stanza.
"I heard our goal was offside, I'm pretty sure the ref knew that," Klopp told BBC Sport after the 1-1 draw.
"In 50-50 situations it was always a free-kick for the other team which was hard and did not make life easy."
Speaking to Sky Sports, the Reds' boss added: "As a human being, if I know I have made a big mistake in the first half, I don't want to open the gap any more.
"Referees are obviously human beings, and I understand that, but I didn't during the game because I had no clue that our goal was offside.”
Liverpool had a chance to win the game in injury time through substitute Divock Origi. He hit his effort straight at West Ham goalkeeper Lukasz Fabianski from an offside position, though no flag had been raised.
"The goal and last chance from Origi was a big mistake from the linesman," said Hammers manager Manuel Pellegrini.
"We draw because they scored a goal that was a metre and half offside. We didn't lose the game with the last play of the game because Origi missed a shot, but again was offside."
Liverpool have opened a three-point gap over second placed Manchester City, though Pep Guardiola’s side can go top on goal difference if they win away to Everton on Wednesday.