TAIPEI (AFP) - Activists on Thursday (March 10) vowed to revise Taiwan's animal protection laws after a court upheld a ruling overturning a fine against the owner of a private zoo over the death of a famous performing hippopotamus.

A Ho, a male hippo who regularly performed at the Taichung zoo, died in December 2014 after breaking a leg and sustaining other injuries while being transported from the site.

The zoo owner, identified by only his surname Chang, was fined TW$500,000 (S$21,000) by the Taichung city government but appealed.

The High Administrative Court overturned the fine in September 2015, saying the owner did not abuse the hippo, nor did he injure the animal on purpose that led to its death.

The Supreme Administrative Court rejected Taichung's appeal in its final ruling on Feb 25, which was received by the city government and Chang Thursday.

The two-tonne beast apparently panicked when it jumped from a moving truck, crushing its diaphragm and breaking a leg, only to sustain further injuries the following day when it was crushed inside a container while returning home from medical treatment.

Animal protection activists were disappointed by the court decision and pledged to further revise animal cruelty laws amended last year following the hippo's death.

"It was a disappointed ruling, but we were not surprised," Mr Chu Tseng-hung, the head of the non-profit Environment and Animal Society of Taiwan, told AFP.

Taiwanese authorities toughened animal cruelty laws in January 2015 but Mr Chu said they needed to be further revised.

"A Ho should not die for nothing," Mr Chu said.