Paul Nicholls admitted his "sadness" after Kauto Star's time at his Ditcheat yard came to an abrupt end on Tuesday.
The winner of five King Georges and two Cheltenham Gold Cups had been officially retired in late October and was expected to remain at Manor Farm Stables in Somerset until Boxing Day, when he was due to parade at Kempton.
Owner Clive Smith had announced on Monday that the 12-year-old would be moving away to be prepared by European bronze medalist eventing rider Laura Collett and long-time Great Britain manager and coach Yogi Breisner for a new career in the world of dressage - a decision not popular with Nicholls and his staff.
The winner of 19 races for the champion trainer, including four Betfair Chases and two Tingle Creeks, Kauto Star had been with Nicholls for eight years and was invariably ridden by his head lad Clifford Baker.
Nicholls told his Betfair column: "It is with great sadness that I have to report that Kauto Star has left the yard for the last time. It has been no secret that Kauto's future has been a great source of debate since we announced his retirement. And, to be brutally honest, this morning I felt the time had finally come for me to take control of the situation, and to start making the decisions.
"Now, I am fully aware that Kauto is Clive's horse and he can do as he wishes, even though I would personally have loved Clifford to have looked after him for the rest of his years. But what upset me and my team here is when Clive announced that he had spoken to experts about the horse's future - but failed to consult and listen properly to the team that had looked after him here for the past nine years. That really upset us."
Nicholls went on: "So we had a team meeting here this morning. And after listening to everybody involved - there were about six of us in the meeting - I rang up Clive, said I don't want to fall out, but we think it is in the best interests of everybody concerned to take Kauto to Yogi Breisner's this afternoon so that he could start his new career in the dressage field as soon as possible.
"Which we did with the saddest of hearts. But I like to think with a lot of dignity, too. And, yes, there were plenty of tears too. He was a member of the family here at Ditcheat, and we will all miss him so much. I would just to like say that it was a privilege for us here at Ditcheat to train the horse. Good luck, old boy. You were the best - and deserve the best."
Collett, 22, who is an aspiring Olympian based at the Membury Estate in Wiltshire, tweeted: "I feel very privileged and extremely honoured to have been asked to ride Kauto Star. I will be working closely with Yogi to give Kauto Star the best chance of a second career in dressage."
She later added: "Kauto Star has arrived safe and sound. Had a nice roll, now happily munching on his hay!"
2 May 2016Drama at Bath as horses narrowly avoid two people on track
Robin Of Navan set to swerve Lingfield trial for France
Aidan O'Brien - US Army Ranger will learn plenty at Chester
Found finds magic touch for Mooresbridge Stakes success
Derby tilt not ruled out for Guineas runner-up Massaat
Awtaad too good for Blue De Vega in Tetrarch Stakes at the Curragh
Aidan O'Brien - Classic trials likely to be key to Minding plans
Bryan Smart reveals Dante option at York for Kentuckyconnection
Steve Rogers drawn stall three in Chester Cup for Roger Varian
Somehow bids to continue Aidan O'Brien dominance in Cheshire Oaks
Aidan O'Brien ponders Irish 2,000 Guineas run for vanquished Air Force Blue
Australian ace Chautauqua to duck Royal Ascot
Prix Ganay glory for Dariyan and Alain de Royer-Dupre
Swiss Range speeds to Pretty Polly success for Frankie Dettori and John Gosden
Minding all business for 1000 Guineas glory at Newmarket
Oasis Fantasy returns to winning ways at Newmarket
Usherette on top for Andre Fabre and France in Dahlia Stakes
John Gosden happy with Crazy Horse and Royal Artillery after Newmarket gallop
Fascinating Rock and Found clash in Mooresbridge showdown at the Curragh
'No obvious cause' for Jack Hobbs Newmarket flop - Godolphin
Hugo Palmer to delay Derby call with Guineas star Galileo Gold
1 May 2016Kevin Prendergast puts Awtaad on Classic trial in Tetrarch Stakes at the Curragh
'Incredible' Maurice rules in Champions Mile at Sha Tin
Roger Varian backs Belardo to bounce back at Newbury
Roger Varian has Intilaaq in 'great shape' for Sandown mission
Warren Greatrex aims high with Punchestown hero One Track Mind
Iain Jardine considers Haydock heat for 'improving' Shrewd
National hero Pineau De Re bows out at Uttoxeter
Whiteout holds Limini for surprise Punchestown victory
Galileo strikes Guineas gold for Frankie Dettori and Hugo Palmer
Exosphere sparkles as Jack Hobbs is pulled up in Jockey Club Stakes
US Army Ranger leads Aidan O'Brien entries in Chester Vase
Knight Owl swoops for James Fanshawe at Newmarket
Profitable lives up to his name with Palace House triumph at Newmarket
Covert Love to miss Middleton Stakes at York
David Elsworth has Arabian Queen in bloom for Dahlia Stakes at Newmarket
30 April 2016Tommy Dowling suffers multiple injuries in Fontwell fall
Eddie Lynam and Sole Power charged up for Newmarket House raid
Eddie Lynam and Sole Power charged up for Newmarket House raid
Marcel set to feel the Force in 2000 Guineas
Fringe a cut above at Punchestown once more
Gavin Cromwell joy as Jer's Girl has the power at Punchestown
Vroum Vroum Mag hits top gear at Punchestown for Willie Mullins and Ruby Walsh
Minding out to master 1000 Guineas rivals at Newmarket
Classic 'acid test' looms for 2000 Guineas favourite Air Force Blue
Limini sights set on Mares Champion prize at Punchestown
Jack Hobbs returns in 'proper' Jockey Club Stakes at Newmarket
29 April 2016Jack Kennedy dazzles aboard Punchestown winner Definite Ruby
Avant Tout sweet at Punchestown under cool Paul Townend
Shin A Vee glee at Punchestown for Denis Cullen
Sir Michael Stoute throws Cannock Chase in Huxley hat at Chester
Iain Jardine keen on Nakeeta for Chester Cup glory
David Wachman calls time on Legatissimo career
John Gosden considers racecourse gallop for Derby dark horse Royal Artillery
Lingfield Friday card switched to the all-weather
Apple's Jade seeking Champion honours at Punchestown
Minding heads sweet sixteen for 1000 Guineas at Newmarket
Champion jockey Silvestre de Sousa not banking on title defence
Michael O'Leary admits to Don Cossack career fears
All options open next year to dazzling Douvan after festival hat-trick
This is where we want to be - Warren Greatrex on top with One Track Mind
Nicky Henderson gets on Punchestown scoresheet with Cup Final
Quantitativeeasing adds up to La Touche glory for Enda Bolger
Galileo Gold all the rage in 2000 Guineas market
Bright New Dawn lights up Punchestown Festival
'Not a bother' on National hero Rule The World after Punchestown
Willie Mullins pursues Punchestown prize with revved-up Vroum Vroum Mag
Gavin Cromwell has Jer's Girl 'in great nick' for Punchestown date