Former BBC horse racing commentator Sir Peter O'Sullevan is in hospital after suffering a mild stroke.
Nigel Payne, chief executive of the Peter O'Sullevan Charitable Trust, said the 95-year-old was taken to London's Charing Cross Hospital on Sunday.
Payne said: "Sir Peter had a mild stroke, which he detected himself."
Sir Peter retired in 1997 after 50 years commentating on horse racing's biggest events, including the Grand National and Cheltenham Festival.
His close friend Mike Dillon, from bookmaker Ladbrokes, said: "He's very lucid and seems fine."
Affectionately known as "the voice of racing", Sir Peter began commentating for the BBC in 1948 and called the Grand National for the 50th and final time in 1997, a race won by Lord Gyllene and delayed two days after an IRA bomb threat caused Aintree to be evacuated.
He closed his career with Suny Bay's victory in the Hennessy Gold Cup at Newbury.
Also a successful racehorse owner and journalist, O'Sullevan was knighted in 1997 and in the same year the passionate supporter of animal welfare set up his Charitable Trust, which has since raised huge amounts for animal and racing related charities.
Earlier this month he attended all four days of the Cheltenham Festival.
He is due to have further tests on Tuesday and Wednesday but Dillon added: "He's been for a walk round with the physio.
"Peter was in good form, and the staff are hopeful he'll be able to go home on Wednesday or Thursday."