Former La Liga referee identifies three key mistakes officials made during Barcelona defeat to Inter Milan, Xavi is right to be livid

The key refereeing mistakes against Barcelona during their controversial Champions League defeat at Inter Milan have been identified by a former La Liga referee.

Xavi was left furious with a number of decisions made by official Slavko Vincic during his side's 1-0 reverse in the San Siro on Tuesday night.

Several decisions went against Barca and former Spanish official Eduardo Iturralde highlighted THREE crucial moments that went against Xavi and his side in their key group-stage clash.

The biggest refereeing mistake occurred when Inter defender Denzel Dumfries handled the ball late on.

Despite the ball clearing striking the Dutch defender's hand, a penalty was not awarded and VAR was inexplicably not used to review the incident.

Iturralde claims Barca were denied another penalty when Robert Lewandowski was pushed to the ground in the box.

But the referee failed to award a spot-kick and chose to not consult the pitchside monitor.

The decision not to send off Inter's goalscorer Hakan Calhanoglu was also scrutinised.

The Turkish star landed a crunching tackle on Sergio Busquets, with the referee only brandishing a yellow card.

"There is an extremely clear red card on Calhanoglu for his tackle on Busquets," Iturralde said.

"There are two penalties not called, one for handball, the other one after pushing Lewandowski. I know that sometimes you can make mistakes, but this..."

Barca are set to launch a formal complaint to UEFA over the controversial refereeing decisions, according to reports in Spain.

Speaking after the 1-0 defeat, Xavi made his feelings known.

"I'm p***ed off by the situation we had to live through," he exclaimed.

"It is an injustice. I already said yesterday that the referees would have to speak because I do not understand anything. He didn't want to give me explanations at the end of the game."

The La Liga outfit have won just one of their opening three group-stage matches, beating Viktoria Plzen on matchday 1.