It is understood Kenya, an African elephant, died from a heart attack after being harassed by dogs recently.

A spokesman for the USPCA, David Wilson, told the Belfast Telegraph the organisation, accompanied by a vet from the Department of Agriculture, interviewed staff at Circus Sydney last Friday after learning of the elephant's death.

It is unclear exactly where the incident occurred, but it is understood the animal died within the last two weeks.

Mr Wilson said a post-mortem was carried out by a local vet after the elephant had died from a heart attack.

"The explanation for the heart attack - coming from the circus - is that it was hassled by dogs," he said, adding: "They did make arrangements for proper incineration.

"We do know the animal was properly disposed of. It was taken to a rendering plant in the Lisburn area."

Mr Wilson said that, while the circus was helpful in providing information, they are still investigating the circumstances that led to the elephant's death.

"We do need to get more information about what is going on and how the animal met its end.

"So we will still be investigating the circumstances."

He added that the USPCA continue to lobby for new legislation which stops animals being used in circuses.

"The USPCA is utterly opposed to circuses with animals," he said. " Unfortunately, the legislation we work (with) in Northern Ireland at this time leaves us in limbo.

"We don't have the kind of legislation we need. But there is new legislation hopefully coming in this year which says keeping an animal in conditions likely to cause suffering will be against the law."

Craig Redmond, campaigns manager for the Captive Animals' Protection Society, said: "It is time to end the use of all animals in circuses and we would encourage people to only visit those circuses that have entirely human acts."

No-one from the circus was available for comment when contacted yesterday.