The girl was left with 'appalling injuries' following the attack which she claims happened at one of jockey's homes in Chiseldon, Swindon.
Brendan Powell Jnr, 21, Sean Mooney and Richard Condon, both 20, were arrested.
Police arrested Mooney before he was about to race in Doncaster. They detained him whilst he was in the jockey's weighing room.
The news of the arrests of the up-and-coming jockeys has already rocked the tight-knit world of racing.
One source told the Sun: 'They are all very good jockeys and very popular. It will come as a huge shock to punters and everyone who knows them.'
Mooney had been due to ride Cincuenta Pasos in an apprentice handicap at 4.05pm before police arrived. Racecourse bosses scrambled to find a replacement jockey to take his place.
Police arrested Powell Jnr at his home with Irish jockey Condon who races on the Marlborough Downs in Wiltshire for trainer Neil King.
A stand-in had to replace Powell Jnr as he was due to ride Our Reward in a National Hunt novices hurdle race at Liverpool's Aintree course on Saturday while he was in police custody at the time.
Powell Jnr's family is well known in racing as he is the son of a Grand National winner and top trainer, Brendan Powell Snr.
The 21-year-old became a professional at just 16 and has ridden 14 winners this season alone.
They have been released on bail until a date in late December pending further inquiries.