Racing:Lester Piggott's condition is not believed to be life-threatening as he recovers from a recurrence of a heart problem in a hospital in Switzerland.
Arguably the greatest jockey of all time, the 71-year-old is being treated in Lausanne, where he has been joined by his wife Susan and daughter Maureen Haggas.
Haggas is the wife of Newmarket trainer William Haggas, who told Racing UK: "I think it is fairly common knowledge that he had a bit of a heart problem at Christmas time and he had a recurrence of that in Switzerland.
"Susan and Maureen flew out there on Tuesday morning, fairly worried as you can imagine. But Maureen rang me up and said everything was under control and he was in intensive care as a precaution. In her opinion he is going to get better, which is fantastic.
"Everyone knows that if you have been in hospital with a heart condition and you go back in and enter intensive care it is a worry and it is a fear. But I am assured by Maureen - and I know from the tone of her voice that there is no worry in it - that he is going to be fine."
Piggott was due to attend a special race day in his honour at Newmarket on Saturday, his local course having been the setting for many of his greatest triumphs.
Haggas added: "He and Maureen discussed it and he had every intention of leaving Switzerland on Friday and being at Newmarket races on Saturday. Obviously that is not possible, but I took that as a very positive sign because he is certainly not talking like a man who is in trouble.
"He is terribly honoured about the day and is very touched by it. He is distraught he is not going to be there."
The 11-times champion was suffering problems with his health a few months ago and was first admitted to West Suffolk Hospital in Bury St Edmunds after feeling unwell on Christmas Eve on his return from a trip to Hong Kong. He was released five days later.
As well as the 4,493 career wins before retirement in 1994, and his nine Derbys, Newmarket were preparing to celebrate Piggott's seven victories in the Guineas and the news has rocked the town's racing community.
Alistair Haggis, spokesman for Newmarket racecourses said: "Our thoughts and prayers are with Lester and his family. Everyone in racing, especially in Newmarket, hopes he pulls through.
"He's the town's most famous resident. He's a true legend."
It is 50 years since the first of Piggott's seven Guineas winners, after whom the races on 'Lester Piggott Day', sponsored by Betdirect, are named.
The National Horseracing Museum has borrowed pictures, trophies and memorabilia from Piggott's home to create a special display in a racecourse marquee.
Haggis went on: "It's very sad. He had been so looking forward to his big day on Saturday. I saw him with Lisa Hancock (managing director) last week and he was in great form and really looking forward to it.
"We will talk to Lester's family before the weekend and get an update on how he is, but as things currently stand the raceday is planned to go ahead and will be a great tribute to him.
"Lester was due to host a party in the Royal Box.
"It was all set to be a wonderful day but it all pales into insignificance. We just hope and pray that Lester is back in Newmarket soon."