Colombia striker Radamel Falcao accused American referee Mark Geiger of bias in the South Americans' World Cup round-of-16 loss on Tuesday, telling reporters after the match, "He always made calls to favour England."

Colombia were whistled for 23 of the game's 36 fouls and received six of the eight yellow cards in a contentious affair at the Spartak Stadium in Moscow.

Geiger also called a penalty against Colombia midfielder Carlos Sanchez that led to England's only goal during open play. And Falcao expressed his displeasure with what he perceived to be clear favoritism toward The Three Lions.

"I found it peculiar that they put an American referee in this instance," the Monaco man said.

"To tell you the truth, the process leaves a lot of doubts. He only spoke English, some bias was certain. Through small calls he was pushing us [toward] our goal, that was clear for me."

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Aside from the foul discrepancy, Colombia nearly matched England in possession and total shots, and managed to register two more shots on target before the match went ultimately to penalties, where they fell 4-3.

"The referee disturbed us a lot, in the 50-50 plays, he always made the calls in favor of England," Falcao said. "This situation was undermining us. He didn't act with the same criteria for both teams.

"When in doubt, he always went to the England side. It's shameful that this happens in the round of 16 of a World Cup."

Tuesday's match was not the first time Geiger has been accused of improper behaviour at this summer's World Cup.

FIFA and sources close to the referee last month denied accusations from Morocco's Nordin Amrabat that Geiger asked for a Portugal player's shirt during the North African country's 1-0 loss to the Portuguese.

Carlos Sanchez conceded his second penalty of the tournament. MLADEN ANTONOV/AFP/Getty Images

Morocco also complained about the 43-year-old's performance after the match, which was his first on-field assignment at the event, and midfielder Amrabat raised the prospect of bias by Geiger in an interview with Dutch broadcaster NOS.

"I don't know what [Geiger] is used to, but he was very impressed by Cristiano [Ronaldo]," Amrabat said. "I've been just told by Pepe that in the [first half], he asked if he could have his shirt. Come on, man. What are we talking about? ... We are at the World Cup, not a circus here."

Tuesday's match was the third in which Geiger has been in charge. The other was South Korea's 2-0 victory over Germany in the group stage.

Back in 2014, Geiger became the first American to referee a World Cup knockout-stage game when he worked France's 2-0 round-of-16 win over Nigeria.

Geiger also was the referee for Colombia's World Cup opener in 2014 -- a 3-0 victory over Greece.