Fallon later told a stewards’ inquiry that he had given the horse “a breather” and was afraid he would become “legless” if he kept up the pace, the court was told.

The Jockey Club had tipped off officials at Lingfield racecourse before the race in March 2004 that a large amount of money had been placed on the horse to lose.

The sport’s ruling body later found that Fallon had made an error of judgment in the race.

Mr Caplan said the Jockey Club was not aware of the full picture at the time.

A prosecution expert had since found the ride to be “not a marginal case of a jockey dropping his hands”.

Mr Caplan said: “He notes that passing the two-furlong marker Ballinger Ridge was five or six lengths in front.

“But Fallon then dramatically slows his momentum to the point where he is doing virtually nothing.

“Prior to the one-furlong marker Fallon turns and looks back. The other runners are four to five lengths behind. Fallon eases the horse down, which would send the message to the horse that the race was over.”

The Australian expert had then found Fallon looking round again at the half-furlong but “only tries to get going again” when another horse, Rye, is going past.

“By that time Ballinger Ridge has lost momentum. There is no legitimate reason that a jockey would need to be looking back and steadying his horse down with a furlong still to go.

“When you look at all the evidence in this case, you can be sure Mr Fallon wanted Rye to be the winner.”

Mr Caplan said betting syndicate boss Miles Rodgers had placed £74,000 (€107,000) on Ballinger Ridge to lose the race.

He alleged that fellow jockey Fergal Lynch acted as an intermediary between Rodgers and Fallon in a conspiracy to make horses lose and win money for crooked backers.

On the day of the race, he said Rodgers phoned Lynch nine times before the race. Lynch sent a text message to Fallon a little under two hours before the race.

Fallon, Rodgers and four other men deny conspiring to make 27 horses lose, defrauding the online betting exchange Betfair and other punters between December 2002 and September 2004.

The accused are: jockeys Fallon, 42, formerly of Newmarket, Cambridgeshire, but now of Tipperary, Ireland; Fergal Lynch, 29, of Boroughbridge, North Yorkshire; and Darren Williams, 29, of Leyburn, North Yorkshire; Lynch’s brother, Shaun Lynch, 37, of Belfast; former racing syndicate director Miles Rodgers, 38, of Silkstone, South Yorkshire; and Philip Sherkle, 42, of Tamworth, Staffordshire.

Rodgers also denies concealing the proceeds of crime. All the defendants are on bail.

Mr Caplan said the Jockey Club called police in and an undercover investigation was started in mid-May 2004, leading to arrests in September that year.

On May 15, 2004, Fallon won on Russian Rhythm, a horse trained by Michael Stoute, at Newbury in a race of “some significance and value”.

The race was the only Group 1 race involved in the conspiracy and Rodgers, who was thought to be working with others in Spain, had backed the horse to lose.

He lost £160,256 (€231,657) when the horse won by half a length, it was alleged.

Mr Caplan said Fallon telephoned Fergal Lynch four hours before the race and later sent a text to Shaun Lynch.

Shaun had made calls during the day to Rodgers, and Rodgers rang him five times after the race.

Mr Caplan told the jury: “Rodgers and the other conspirators were clearly expecting the horse to lose under Fallon but something went wrong.

“The prosecution cannot say what precisely went wrong but we can say that Shaun Lynch was seen as being an unreliable intermediary between Rodgers and Fallon after this, and eventually was replaced by Sherkle.

“The prosecution will invite you to draw the inference that something happened in the communication between Fallon and Shaun Lynch in the pre-race period.”

Mr Caplan said that, in the next 10 days, Shaun and Rodgers went to Leicester racecourse to try to meet Fallon face to face.

They also made a trip to Newmarket with Sherkle and another man “in mysterious circumstances” in an attempt to see or confront Fallon, said Mr Caplan.

And two pay-as-you-go mobiles with unregistered details were activated to be used by Fallon and Sherkle, it was alleged.