“It became personal with him,” John Magnier told the High Court, speaking about his head-to-head with fellow billionaire Maurice Regan.

“You could say it became personal with me too.”

Barrister Martin Hayden, acting for Richard Thomson-Moore, had asked if Mr Magnier had ever considered letting Thomson-Moores get the extra €7.25m Maurice Regan was offering them.

“You knew the family circumstances, the difficulty with selling a property that the family had been connected with for hundreds of years, and the assistance you wished to give for the early payment,” said Hayden.

“This was brought on by threat and it was personal with Regan and I did not want to give in to the Regan pressure,” Mr Magnier replied.

“He was applying pressure to anyone and everyone associated with the case – and I wasn’t going to give in to that. And it’s unfortunate that these people were misled by him.”

However, Mr Magnier rejected the suggestion by barrister Martin Hayden that the billionaires were “at war”, describing them as being “at loggerheads about buying land, but we’re not at war”, alluding to Regan’s continued use of Coolmore stallions on his thoroughbred mares.