"This appointment of 'home town' officials contravenes the WBO's guidelines that officials should be neutral, and clearly leaves the contest open to speculation about bias and impropriety," Mr Higgins said.
WBO president Paco Valcárcel wrote to the BBBoC politely requesting that 'the same procedure applied by the British Boxing Board of Control in the Anthony Joshua versus Wladimir Klitschko bout, should be used on this occasion'.
"Inexplicably the BBBoC has ignored that. This is disgraceful," said Higgins.
Higgins said the appointment of O'Connor as the referee breaches the fight contract.
"It's entirely contrary to the spirit of the deal and the letter of the contract struck with Hennessy Sports for the title fight, the governing principal being that it would be a fair fight.
"The entire world knows that Hughie Fury is going to run away from Joseph Parker, clinch, elbow, headbutt and do whatever he can to steal a result. Having a referee with whom he is familiar clearly provides an unfair advantage," Higgins said.
"We might have expected this sort of thing had the bout been held in a banana republic, but to see this lack of neutrality and fair play in a nation like Great Britain is staggering."
Duco Events lobbied BBBoC to have a New Zealander added to the judging panel to balance the presence of a British judge, however the BBBoC had refused repeated requests to appoint a neutral referee.
It's another blow for the fight following reports it's failing to attract fans.
Little over a week out from the bout in Manchester, boxing promoter Bob Arum claims not even 3,000 tickets have been sold. The capacity for the venue is up to 21,000 for a boxing bout.
Arum told the Radio Sport Breakfast, Fury's promoter Mick Hennessy is doing a poor job.
"That's what happens when you deal with amateurs," Parker's American promoter said.
"The people in the UK who are promoting it are not the top level of promoters."
Higgins told Radio Sport he's heard mixed reports about ticket sales.
"There's a lot of rumour in boxing. So Arum does say it's around that figure, the Fury camp are telling me it's a lot more than that so I don't know what to believe," he said.
"Our concern is Duco and Joseph Parker we have a seven-figure chunk of money in our lawyer's bank account and we have the New Zealand television rights. How many tickets they sell in Manchester is their business."
