THE sad news that shook the racing world this week was the death aged 55 of Walter Swinburn, one of the most renowned jockeys of his generation and the rider of the brilliant Shergar.

Swinburn shot to prominence as a 19-year-old after gaining the first of his Epsom Classic victories aboard the legendary Shergar in 1981.

The jockey, nicknamed the Choirboy, went on to win the Derby five years later aboard Shahrastani and again on Lammtarra in 1995.

He also enjoyed international success, winning the Prix de l'Arc de Triomphe in 1983 aboard All Along, on whom he also won the Washington DC International.

More North American success came in the EP Taylor Stakes, a race he won twice, and the Breeders' Cup, where he won the Turf aboard Pilsudski.

Pilsudski, like Shergar, was trained by Sir Michael Stoute, who said: "On the big days he was nerveless and he lived for those occasions. We had many, many very happy, successful days. It's just so sad."

Swinburn took over the training licence from his father-in-law Peter Harris in November 2004, sending out more than 260 winners from his Hertfordshire base before handing in his licence at the end of October 2011, citing financial reasons.

A shocked Harris said on Monday evening: "I've been in Scotland all day and got home this evening and all I know is that he has died. I don't know any more details at the moment."

After his riding days were over, Swinburn enjoyed a successful period as part of the Channel 4 Racing team, working with former National Hunt great John Francome among others.

Francome said: "I spoke to him a couple of months ago and he seemed in really good form. It's absolutely shocking he should die aged 55 – no age at all.

"He was an absolutely gifted rider, you never saw any horse pulling with him or having their head in the air.

"He was a little bit of a troubled soul in some ways, he had weight problems which probably affected him a lot more than other people, but that said that seemed to be a long time ago and he seemed to all intents and purposes fine, but obviously he wasn't.

"He could ride a race, he had a really good feel for what was going on underneath him, what the horse was doing. He must have been a fantastic jockey to have riding for you.

"He'd give great feedback and come back in and tell you everything you needed to know. He probably knew everything he needed to know by the time he got down to the start.

"He was a very sensitive person, both on and off a horse."

Swinburn suffered a terrible fall at Sha Tin in February 1996, when his mount Liffey River crashed through the rails, and he was in intensive care for a week with severe head and chest injuries.

He returned to win on his first ride back on Talathath at Windsor just six months later.

Francome added: "It was a shocking fall and he made an amazing comeback, but he was happiest on a horse.

"He was great company and gave great insight (during television coverage). Flat racing is a little bit sharper than jumping and he could see what was going on in a jockey's mind.

"He had a good smile, great sense of humour, fabulous parents – just a really nice family and I'm devastated for them."

Newmarket-based James Fanshawe was assistant to Shergar's trainer Sir Michael Stoute when Swinburn was the stable's number one rider, and described him as "a brilliant jockey".

"Walter and I were at Sir Michael Stoute's together and he was a brilliant jockey," said Fanshawe, now a successful trainer in his own right.

"Obviously he won the Derby in 1981 at the age of 19 and won the Derby two more times, but he had the most sympathetic pair of hands as a rider. He was a real horseman and was good on the most difficult of horses.

"We worked there together for seven years, it's very sad."

For the second weekend in a row, champion jump jockey Richard Johnson is set to lead Nigel Twiston-Davies' challenge for another big hurdles prize this weekend after being approached to ride Ballyoptic in tomorrow's Long Walk Hurdle at Ascot.

Fresh from steering The New One to victory in the International Hurdle last Saturday, Johnson is the trainer's first choice to replace the injured Ryan Hatch, who suffered multiple fractures in a spill at Cheltenham last Friday.

Johnson said: "I'm very lucky to pick up the ride and Ryan Hatch's bad luck has been my luck. It's good to hear he's doing well and nice to get the ride.

"Looking at the Newbury race, you'd think he has to improve to beat Harry Fry's horse, but Nigel's horses are in great form and Ascot's a staying track. It's a stiff three miles there and Ballyoptic is a strong stayer. I've won the race four times, but would like another."

Johnson guided The New One to an all-the-way win at Cheltenham, tactics which he could also be asked to employ on Ballyoptic.

Ballyoptic won his first four starts for the stable, including the Grade One Sefton Novices' Hurdle at Aintree, but the sequence was halted when he fell at Wetherby in October. He started favourite for the Long Distance Hurdle at Newbury last month, but was comfortably seen off by Unowhatimeanharry, who will re-oppose tomorrow.

Twiston-Davies said: "We are going to try different tactics and ensure Ballyoptic is much handier away. We always thought he was getting a bit slow now, so we'll use more forcing tactics."