Champion Japanese stallion Deep Impact is reported to have died aged 17.
The leading light at Shadai Stallion Station, Deep Impact was euthanised after he suffered a cervical fracture which made it impossible for him to stand.
He was withdrawn from stud duties earlier this year because of a neck issue.
The seven-time Group One winner was a son of champion stallion Sunday silence.
He was twice crowned Japan's Horse Of The Year (2005, 2006) and was champion sire for seven consecutive years from 2012 to 2018.
Among his 42 Group One winners are Saxon Warrior, Tosen Stardom, Real Steel and Mikki Isle who will all stand in Australia this spring.