Damaen Kelly was on the wrong end of a shocking decision in his European bantamweight title challenge against Simone Maludrottu in Belfast on Friday.
Kelly dominated the first half of the bout but still lost out
The champion was handed a unanimous decision despite appearing to have been out-boxed for most of the fight.
The ringside judges scored the bout 115-113, 118-111, 116-113.
Promoter Tommy Gilmour said: "That was shameful. It was the biggest robbery I've seen in 35 years of boxing."
Gilmour called for the British Boxing Board of Control (BBBC) to lodge a complaint with the European Boxing Union.
"The British Boxing Board should not tolerate that decision because this game is hard enough," he added.
"They should refuse to let any British fighters fight for the European title. This is a tragic night for boxing.
"The punch stats said that Kelly landed 155 punches while the Italian landed only 87, so how on earth could he get the decision?"
Home-town fighter Kelly, a former European flyweight champion, said: "I thought I walked it. I thought I was the European bantamweight champion."
However, BBBC chairman Charles Giles refused to criticise the judges after the fight.
"It was an excellent contest and I thought it was a close contest," said Giles.
"The EBU has a high standard of judges and referees. It is not my job to judge the contest, I leave it to the judges.
"If we have a complaint from any of our license holders, we will act accordingly. Everybody has their own opinion and I'm not going to make any rash decisions."
It was Kelly's first contest in 12 months and the bout only came about when a planned IBF flyweight title fight in Sydney with champion Vic Darchinyan was called off.
Maludrottu, who was making his fourth defence of the title, improves to 22 wins and one loss.