Grand National runner Celebre d'Allen has died following Saturday's race at Aintree.

The 13-year-old horse was pulled up after the final fence and collapsed on the track.

He received medical treatment on the course before being taken to the racehorse stables for further assessment.

After initially showing signs of recovery, he died after his condition "deteriorated significantly".

"We're heartbroken to share that Celebre d'Allen has passed away," trainers Philip Hobbs and Johnson White said on Tuesday.

"He received the very best treatment by the veterinary teams and was improving.

"However, he deteriorated significantly last night and could not be saved. He was a wonderful horse and we will all miss him greatly."

Micheal Nolan, Celebre d'Allen's rider, was handed a 10-day suspension on Saturday after Aintree stewards ruled he had continued when his mount had no more to give and was losing ground.

The British Horseracing Authority (BHA), which passed the suspension on Nolan, said Celebre d'Allen passed the necessary checks to race at Aintree.

"As with all runners in the Grand National, Celebre D'Allen was provided with a thorough check by vets at the racecourse," a BHA statement read.

"This health check includes a trot up, physical examination of limbs to check for any heat, pain or swelling, and listening to the heart to check for any murmur or rhythm disturbance.

"This marks the final step in an extensive process of checks to ensure a horse's suitability to race in the National, which also includes a review of veterinary records and assessment by a panel of experts to consider a horse's race record and suitability to race."

Celebre d'Allen's death prompted criticism from animal rights groups.

"The blame for his death lies not with any individual, but with the 'sport' of horse racing itself," said Animal Rising spokesperson Ben Newman.

"Again and again, we see horses pushed far beyond their limits, to the point of injury, collapse, and death."

Animal Aid campaigns manager Nina Copleston-Hawkens said: "To allow a horse of this age to be ridden to death in the most gruelling race in the country is disgraceful - and the blame for his end lies fairly and squarely with the British Horseracing Authority."

World Horse Welfare chief executive Roly Owers said: "We are deeply saddened to hear about the death of Celebre d'Allen after last Saturday's Grand National and our heart goes out to all those who cared for him. Every effort must be made to learn lessons from this very sad outcome."

The BHA said it would analyse the "race and incident in detail", as well as sending the horse for a post-mortem investigation.

Celebre d'Allen was a 125-1 shot at the National, which was won by jockey Patrick Mullins on Nick Rockett.