Dick Francis, best-selling thriller writer and rider of Devon Loch, has died at the age of 89.

His son, Felix, said he was ‘devastated’ as he paid tribute to his ‘extraordinary’ father.

Francis, from Oxfordshire, the author of 42 novels, was ‘rightly acclaimed’ as one of the greatest thriller writers in the world, his spokesman said.

Francis was the man aboard the Queen Mother's Devon Loch in the 1956 Grand National at Aintree. The horse's collapse 50 yards from the winning post with the race in his grasp remains one of the great mysteries of the turf.

An enthusiastic crowd thought they were about to witness the first Royal victory in the Grand National for 56 years when the nine-year-old took up the running three fences from home.

Devon Loch was clear of his nearest pursuer ESB when he suddenly sprawled and slithered to the ground, turning a National dream into a nightmare.

Whether it was the tumultuous cheers from the stands that startled the horse or that he was trying to negotiate the water jump on the other side of the rails, Devon Loch was cruelly denied his place in the National roll of honour.

In 2006, Francis officially opened a new weighing room, winner's enclosure and paddock at Aintree - the first phase of a £30 million development of the historic Liverpool course.

He said at the time: ‘The Devon Loch episode was a terrible thing but I look back on it now and I can say that if it hadn't happened I might never have written a book, and my books have certainly helped keep the wolf from the door.

‘After Devon Loch, I was persuaded to write my autobiography and after that I wrote for the Sunday Express for 16 years and that taught me how to write, it taught me what words to leave out.

‘The Devon Loch episode is still a terrible memory, even after all these years.

‘I had had a terrific ride for four and a quarter miles on him and he pricked his ears up and I believe that is when the noise of the crowd hit him.

‘It was a tremendous crescendo of noise and it seemed that his hindquarters refused to act just for a split second.’

Francis, who was living on the Cayman Islands in his later years, died early on Sunday, his family said later.

A spokesman said he died of ‘old age’.

Son Felix added: ‘My brother, Merrick, and I are, of course, devastated by the loss of our father, but we rejoice in having been the sons of such an extraordinary man.

‘We share in the joy that he brought to so many over such a long life. It is an honour for me to be able to continue his remarkable legacy through the new novels.’

Francis wrote a volume of short stories, an autobiography and the biography of Lester Piggott.

Even Money, written with Felix, was published in September 2009 and Crossfire, the new Dick and Felix Francis novel, will be published in autumn 2010.

He retired from racing in 1957 and took up writing, first for the Sunday Express and then, in 1962, with the novels.

Francis also had a distinguished military career, serving the RAF in 1940, initially stationed in the Egyptian desert before he was commissioned as a pilot in 1943.

His wife, Mary, to whom he was married for 53 years, died in 2000. He also had five grandchildren and one great grandson.

There will be a small funeral at his home in Grand Cayman, followed by a memorial service in London in due course, his spokesman said.