It was the second time in two days that Newmarket's National Stud, which was narrowly outbid by Zenya Yoshida for Dr Devious, had failed to keep a top colt in Britain.
'It was a very hard decision to make,' Sangster said. 'To be fair to the National Stud, they weren't aware the horse was for sale until the very last moment. I wish it had gone the other way but in the end the mighty yen won the day.
'The logical thing to do was to stand him myself at one of my 10 studs in Ireland, two in the United States or three in Australia,' he said. 'But in this market this is a good deal. I would love to have kept him and bred from him here because he is probably the most desirable stallion in the world.
'The Japanese offer makes him roughly worth pounds 100,000 a share but if I had syndicated him in the USA or Europe I would have had to pay the infertility and mortality insurance for the purchaser.'
Rodrigo De Triano's final run will be next Saturday, when he runs in the Breeders' Cup Classic at Gulfstream Park, Florida.
Results & Catterick card, page 44