Jockey Freddy Tylicki has suffered some paralysis following a fall in a four-horse pile-up at Kempton on Monday.
Tylicki has had spinal surgery and has movement in the upper half of his body but not lower as the result of a T7 paralysis.
He suffered a heavy fall while riding Nellie Dean in Monday’s 15:20 GMT race.
“Freddy remains in intensive care and is not receiving any visitors for the foreseeable future,” said Lisa Hancock of the Injured Jockeys’ Fund.
Tylicki is being treated at St George’s Hospital in Tooting, south London.
Hancock added: “His family would like to thank the St George’s staff for the care he has received. As this is a very difficult time for Freddy and his family, they would like to thank everyone for their good wishes, and for continuing to respect their privacy.”
Champion jockey Jim Crowley suffered a broken nose in the incident, and jockeys Steve Drowne and Ted Durcan were also unseated.
Nellie Dean appeared to clip heels with leader and eventual winner Madame Butterfly as the field rounded the home turn.
Crowley and Electrify were racing immediately behind and were brought down, as was Drowne’s mount Skara Mae. Durcan was also caught up in the melee and was unseated from Sovrano Dolce.
The horses involved were not reported to be seriously injured.