Joseph O'Brien said he was indebted to St Nicholas Abbey, who died on Tuesday, for being the fulcrum of his emerging riding career.

The Aidan O'Brien-trained seven-year-old, winner of six races at the highest level, including three Coronation Cups at Epsom, had to be put down after he suffered another bout of colic.

O'Brien jnr rode him to two Coronation Cup triumphs and also secured notable victories on the worldwide stage in the 2011 Breeders' Cup Turf, where he became the youngest winning rider in the meeting's history, and in the 2013 Dubai Sheema Classic at Meydan.

Reflecting on his Breeders' Turf success, the jockey told the Telegraph: "He will always be very special to me, and so will that day.

"It was my first big win on the world stage, and it was my first big win outside Ireland. He's a horse I will never forget.

"I think his best win was in the Sheema Classic in Dubai, but he was very good in his third Coronation Cup, as well.

"In his last season, he was so much better than he had ever been. He was so relaxed. He loved his racing and he loved his work.

"It is sad to see him go that way, we would all have liked to have seen him go to stud. He has given us all here at Ballydoyle some great days."

St Nicholas Abbey's third Coronation triumph last June - his final racecourse appearance - took his career earnings to almost £5million.