LONDON (AFP) - Owners of a prize-winning Irish Setter who died after competing at the renowned Crufts dog show claimed on Sunday their dog had been poisoned at the English event.

Thendara Satisfaction, who was known as Jagger and was almost four years old, came in second in his class at the event in the city of Birmingham on Thursday.

The dog died after returning home to Belgium, 26 hours after leaving the event, a spokeswoman for Crufts operators The Kennel Club said.

"We have spoken to his owners and our heartfelt sympathies go out to them," the spokesman said. "We understand that the toxicology report is due next week and until that time we cannot know the cause of this tragic incident."

Co-owner Dee Milligan-Bott wrote on her Facebook page that Jagger had been killed by being fed cubed beef with poison "stitched into the meat".

"This resulted in a very painful death for our beautiful boy," Milligan-Bott wrote.

"The timings from the autopsy make it clear the only place this could have been given to Jagger was while on his bench at Crufts. The police have been informed."

Fellow owner Aleksandra Lauwers wrote: "He loved man and he has been killed by a man!"

"To person who has done it, hope you can sleep well knowing you have killed our love, family member and best friend to our son," Lauwers wrote on the social network.

Almost 22,000 dogs compete at Crufts, something of a British institution, including almost 3,000 from abroad.

An increased influx of foreign dogs had raised concerns that underhand tricks such as drugging competitors' dogs or putting chewing gum in its coat could become more common.

Prize money at the event is paltry, with just £100 (S$207.20) awarded for best in show, but owners of winning dogs can make a lot of money from breeding.