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!"
24 January 2017Bargain-buy Desert Queen shines in Leicester feature
Bob Baffert 'honoured' to have another world's best horse in Arrogate
Inspection called for Fakenham card
Cheltenham hopes dashed for American raider Rawnaq
Most Celebrated in Triumph Hurdle picture after Wetherby romp
Bishops Road booked for Grand National Trial defence
National hero Many Clouds primed for Thistlecrack clash
American ace Arrogate named best in the world
Vroum Vroum Mag handed Doncaster engagement
Ar Mad bypasses rearranged Clarence House to wait for Ascot Chase
Min the headline act in Arkle at Leopardstown
Faugheen stars in six for Irish Champion Hurdle
Dewhurst victory the key as Churchill secures champion two-year-old honours
Leicester gets the green light following third inspection
Barry Geraghty thrilled by Jezki reappearance win
Kimberlite Candy team consider weekend options
Wetherby gets the go-ahead following second inspection
California Chrome team confident he can overcome wide Pegasus draw
Churchill crowned leading juvenile performer of 2016
Faugheen and Annie Power clash not ruled out by Willie Mullins
Frost forces another Wetherby check
Leicester call third inspection
Paul Nicholls ponders Politologue plans
Top Gamble back in Clarence House Chase frame at Cheltenham
More Of That given Cheltenham cross-country chase option by Jonjo O'Neill
Harry Fry gives white-hot Unowhatimeanharry Cleeve Hurdle entry
Nicky Richards set to launch dual Doncaster raid in Sky Bet Chase
Kerry Lee considers Thistlecrack Cheltenham clash with Kylemore Lough
Ladbrokes replaces Hennessy as sponsor of Gold Cup at Newbury
Gordon Elliott hoping for Leopardstown rain ahead of Don Poli Gold run
23 January 2017Catchamat lays down Newcastle marker for the Waltons
Briery Queen on course for Cheltenham Festival date
Nicky Henderson rules out Clarence House option for Altior
Leicester call early check due to frost threat
Gallant Gray Wolf River set more realistic targets for next outing
Evan Williams thinking of Aintree for Evening Hush
Ice Cold Soul bags big handicap hurdle prize at Leopardstown
A Toi Phil the latest to benefit from magic touch of Jack Kennedy
Faugheen on course to return for Irish Champion Hurdle defence
Yorkhill still unbeaten over fences after Leopardstown win
All options open for Harry Fry's Haydock hero Neon Wolf
Smart Flat mare Toe The Line off the mark over hurdles
No rush for Jessica Harrington to map out Jezki target
22 January 2017King George VI Chase move would need BHA approval, says Nick Rust
Alary's Haydock disappointment mystifying Tizzard team
Airlie Beach on course for Cheltenham Festival assignment
David Pipe planning one more run with National-bound Vieux Lion Rouge
Warren Greatrex maps out Towton target for Missed Approach
Frozen track claims Fontwell card
Bristol De Mai's day as Alary falters in Peter Marsh at Haydock
Nigel Twiston-Davies salutes The New One after Haydock triumph
Un De Sceaux to run at Cheltenham for rearranged Clarence House Chase
Neon Wolf cuts loose at Haydock to claim Supreme trial
Waiting Patiently pounces at Haydock for Malcolm Jefferson
Deepsand a shore thing at Haydock for Alexander Thorne
Classy Jezki back in business at Navan
Yorkhill faces examination of chasing credentials at Leopardstown
Heartbreak City bids to transfer top Flat form to valuable jumps prize
21 January 2017Pinzolo too sharp for Lingfield rivals
Hereford forced to abandon Sunday card
Hereford inspection brought forward
Clarence House Chase switched to Cheltenham
Sunday check for Hereford card
Fontwell team call inspection ahead of Sunday meeting
Frozen Taunton loses Saturday fixture
Dual Group One winner The Grey Gatsby joins Dermot Weld
Ascot card called off following early-morning inspection
River flows deep for Tim Vaughan at Chepstow
Project Bluebook earns Cheltenham quotes with Musselburgh success
Colin Tizzard earmarks Cleeve Hurdle charge with West Approach
Injury setback for Andrew Thornton but 'this is 100 per cent not the end'
Peter Bowen ponders hurdling return for Henri Parry Morgan
Alan King puts 'progressive' Elgin on trial at Haydock
Dashing grey Politologue takes next step up the ladder at Haydock
The New One primed for Champion Hurdle Trial hat-trick bid
Colin Tizzard wary of Alary's weighty task in Peter Marsh Chase at Haydock