Barry McGuigan has denied stealing money from the boxer Carl Frampton during their time working together.
Speaking during the 11th day of legal action at the High Court in Belfast, Mr McGuigan said it was "ludicrous" to suggest he had kept any money from Mr Frampton which he had been entitled to.
The boxer is suing Mr McGuigan over alleged unpaid earnings.
Mr Frampton, on the other hand, has been accused of a breach of contract. Both men deny any wrongdoing.
In court on Thursday, Mr McGuigan was asked by his barrister if he had ever stolen or concealed money from Mr Frampton.
"No, never," replied Mr McGuigan
He was then asked if he had ever "siphoned" money into his own account.
"That's ludicrous, no," replied Mr McGuigan
Asked about his priorities at the time, he said: "Two prime objectives - get him to the top, get him to a world title fight and get him as much money as I can."
MTK Global 'despicable'
After an eight-year partnership, Mr McGuigan and Mr Frampton split in 2017. The boxer later moved to the MTK Global management company.
Asked for his view on the company, Mr McGuigan told the court: "They are despicable."
Later, under cross-examination, Mr McGuigan was questioned about being disqualified as a director in Northern Ireland for five years in 1996.
Mr Frampton's barrister, Gavin Millar QC, told the court one of the reasons was that he was in the "habit of paying personal bills out of the company bank account".
The barrister asked Mr McGuigan why he did not tell Mr Frampton about his disqualification when they began working together in 2009.
"I didn't think it was relevant or I would have told him," said Mr McGuigan.
'I didn't do finances'
Mr Millar also asked him why a number of sports companies he was involved with repeatedly made losses during his time working with Mr Frampton.
Mr McGuigan said he concentrated on boxing rather than money matters.
"I didn't do the finances, I just looked after the fighters," he said.
Earlier, the court was told about events leading to the split in the partnership in August 2017.
The previous month, Mr Frampton had been scheduled to fight Mexican boxer Andres Gutierrez in Belfast. The fight was called off on the eve of the bout after the Mexican injured himself.
By that stage, however, Mr Frampton had already failed to make the weight for the fight.
Mr McGuigan said: "He just was ill-disciplined and didn't do it properly."
The partnership ended a few weeks later.
The case continues.