"It's always hard to get a seat 15 minutes before the show even starts," said Tom, who acts as the show's compere.

"So I'm not sure how much more popular we can get."

The pigs are exempt from the ban because they are kept in constant quarantine - from other humans and pigs - as they travel around the show circuit in their specially designed airconditioned luxury trailer, which also has sleeping quarters in the front so the Vandeleurs can stay with their pigs.

"I'm not too sure on the technicalities of it but we were always going to be a goer because they are the only pigs we have on the place," Tom said.

The Australian Pig Breeders Association, the South Australian Pig Society, the Department of Primary Industries & Resources of South Australia and the Royal Agricultural & Horticultural Society of SA decided to prevent pigs being exhibited at the 2009 show to avoid them contracting the H1N109 virus.

This year was to have been the 100th anniversary of showing registered purebred pigs at the Royal.

The Vandeleur act is one of the longest acts to have been run at the show - it has run for 16 years so far, and diving pigs have been part of the performance for nine years.

"It's one of the longest to have been running off the main show arena," Tom said.

"I think it's been so popular because it's such a fast-paced act with the racing and diving."

Tom says the family was the first to race pigs in Australia and was still the only one in the world to run "true" diving pigs.

* Extract from a full report in Stock Journal, September 10 issue.