A horse has been euthanased at the Oakbank Racing Carnival in the Adelaide Hills after being injured during a jumps race.

The horses were racing in the Somerled Benchmark Hurdle when five-year-old gelding Searaven fell at a hurdle, causing Wheeler Fortune to fall.

Searaven was uninjured but Wheeler Fortune, trained by John Wheeler, was euthanased as a result of its injuries.

A small band of protesters gathered outside the event said deaths like these show the sport should be banned.

Protesters line the road at the Oakbank Easter Racing carnival in the Adelaide Hills. ( ABC News )

"We know that jumps racing cannot be made safe," Elio Celotto from the Coalition for the Protection of Racehorses said.

"We know that the number of falls are still as statistically high as they have [ever] been.

"We want the racing industry to come clean and show proper statistics about what happens not only to jumps horses but all horses."

Oakbank Racing Club chairman Barney Gask said it was the first fatality at the track in six years.

"We need to look at that now and work out how we can have that not happen again," he said.

Organisers earlier said their studies showed racegoers were attracted to Oakbank to see the steeplechase and the event remained popular with South Australians.

"We will get more people here than they had at Randwick last week with $10 million prize money on offer," Thoroughbred Racing SA chairman Frances Nelson said.

"It's very popular."

Jumps racing has been banned across most of Australia, but is still practised in South Australia and Victoria.

A South Australian parliamentary committee last year found jumps racing should not be banned.

A steward's report on the death will be published next week.

The RSPCA, however, disputed Mr Gask's figure, and said Wheeler Fortune was the fourth horse to die as a result of jumps racing at Oakbank in the past six years.

This included Black Moon in 2014, Virvacity in 2012, and three other horses in the two years prior to 2012.

The RSPCA called for an end to jumps racing in SA and Victoria and said Wheeler Fortune was the 17th horse to die during SA jumps since 2009.

It said 79 horses had died in jumps racing across Australia since 2006.