T M Opera O, who held the world earnings record for 17 years, has died aged 22 at stud in Japan.

A son of Opera House, he won 14 times from 26 starts, including seven Grade 1s, four Grade 2s and a Grade 3.

He was the 2000 JRA Horse of the Year, winning all of Japan's turf championship distance Grade 1 races that year (Tenno Sho Spring, Takarazuka Kinen, Tenno Sho Autumn, Japan Cup, Arima Kinen), a string of success that made him the world's leading earner.

T M Opera O (8) lands the 2000 Japanese Cup, helping him to a prize-money record that stood until 2017

In addition to his five Grade 1 victories in 2000, T M Opera O also won the 1999 Satsuki Sho, which led to his being named top three-year-old colt that year, while his other Grade 1 victory was the 2001 Tenno Sho Spring.

His career winnings of ¥1,835,189,000 (approximately £12.3 million/€14m in today's reckoning) set a world record that stood from 2000 until 2017, when it was beaten by Arrogate when he won the Dubai World Cup. His Japanese earnings record was also surpassed last year by Kitasan Black.

T M Opera O died at the Hakuba Bokujo Farm in Niikappu-cho, Hokkaido, after suffering a heart attack.

Owner Masatsugu Takezono said: "I understand it was an instant death without any suffering. When I went to see him last autumn he was energetic and he had just finished breeding to two mares this year. It's very sad. I'll never forget his unbelievable success in 2000."

Jockey Ryuji Wada, who partnered him in all his Grade 1 victories, added: "I'm shocked. He was too young to die. His best race would have been the 2000 Tenno Sho Spring, because we were confident and he raced perfectly."