There are no business or commercial documents to prove that Barry McGuigan's eldest son Blain was the promoter of two of Carl Frampton's big Belfast fights, the High Court has been told.
It was also alleged that ticket sales for the Tiger's Bay boxer's world title win over Kiko Martinez at Belfast's Titanic slipways in September 2014 were under-declared by almost £400,000.
On day 17 of the legal battle between former world boxing champions Barry McGuigan and Mr Frampton, Blain McGuigan was accused of lying to the authorities about takings from the outdoor show.
But the 37-year-old musician turned promoter told the court that under-declaration was commonplace within boxing, adding that he'd already agreed to pay the British Boxing Board of Control a £10,000 fixed sum in estimated taxes.
He also denied ever concealing income or offering a 30% share of profits to Mr Frampton, who is also known as The Jackal.
Mr Frampton (33), a dual-weight world boxing champion, is suing Barry McGuigan and Cyclone Promotions for £6m alleged withheld earnings.
In a counter-suit, Barry McGuigan (59) is counter claiming against his one-time protege for breach of contract when he ended their partnership in 2017.
Both men deny the respective allegations against them.
Acting on Mr Frampton's behalf, Gavin Millar QC accused Blain McGuigan of being unable to produce any documentation which showed that he had acted as promoter for the north Belfast boxer's fights with Hugo Cazares and Kiko Martinez in 2014.
"You can't show me any document at all that shows you acting as promoter," Mr Millar said regarding the Cazares bout.
Blain McGuigan replied: "If we were to go to the Board of Control I'm sure we could get the relevant documents."
Mr Millar later said: "Can you show me a single document in relation to the Martinez 2 fight that identifies you as the promoter?" to which Blain McGuigan responded: "Again there would be a lot of documents with the Board of Control. I did a lot of work around that event... there would be a lot of documentation that highlights my work as a promoter."
Referencing Mr Frampton's victory over Mr Martinez for the super bantamweight world title at a purpose-built stadium in 2014, Mr Millar told the court that just under £900,000 worth of tickets were sold for the fight, while a figure of £509,000 in takings was reported. "The total is just under £900,000 - that's your case for the value of sales," Mr Millar said. "You reported the takings to the British Board of Boxing Control as being £509,000."
Blain McGuigan replied: "We may well have done but we'd a pre-agreed agreement with the Board to pay £10,000 so it didn't require us to give the numbers."
Mr Millar said: "It's a huge under-declaration, nearly half of the ticket sales."
Referring to another document, Mr Millar said: "What you've described it as in your letter to the board was 'net takings' - that the net takings were £509,000."
Blain McGuigan replied: "But there's no other correspondence Mr Millar about how the Board would have calculated any tax because it was pre-agreed that I pay them £10,000."
The barrister said: "If you've got an agreement with the Board why do you need to lie to them about what the takings were?"
Blain McGuigan responded: "Whatever happened it's not relevant because we had a pre-agreed fee with them. And as I've said before under-declaration does occur a lot. Every promoter does it."
Costs and expenses for the Martinez fight included £34,000 in cash entries, which Blain McGuigan said would've been commissioned for boxers and managers who sold tickets to the show. Travel and subsistence of £18,000 included reimbursing foreign fighters, ring announcer and additional staff for taxi and flight fares.
Blain McGuigan rejected claims that Mr Frampton was kept out of discussions about purse fees and financial arrangements.
"Carl wouldn't have been satisfied just to have got a number plucked out of the sky," he said.
"Boxers never do that, they don't go in and put their neck on the line without knowing their value."
Another central part of Mr Frampton's case, that he was allegedly promised a 30% share of profits as a director of a Northern Ireland-based Cyclone Promotions company, was also disputed.
"The first time I head about that was when these proceedings started," Blain McGuigan said.
When Mr Millar suggested that income from Mr Frampton's career went through another "secret" Cyclone Promotions UK company, Blain McGuigan said everything was explained during informal meetings.
When also asked about a US dollars account associated with Cyclone, that Mr Millar said was used by members of the McGuigan family to hide earnings from his client, he said: "We did not conceal anything. He knew about it, he was paid from that account. It's a pretty strange way of concealing things."
The hearing continues.