SeaWorld sued over 'enslaved' killer whales

A US judge is considering a historic lawsuit from the animal rights organisation PETA against SeaWorld.

This is the first time a US court has considered a legal proposal on whether animals should have the same constitutional rights as humans.

Five Orcas have been named as complainants in the case brought by People for the Ethical Treatment of Animals. They are Kasatka, Ulises, and Cork, at SeaWorld San Diego; and Katina and Tilikum at SeaWorld Orlando.

The case is unique of its kind and invokes the13th Amendment to the US constitution - the Amendment that abolished slavery and involuntary servitude.

Yvonne Taylor, senior program manager at PETA UK, said that the organisation opposed keeping living, feeling creatures in such conditions.

Theodore Bradshaw, SeaWorld's lawyer, said that if the case were to be successful it would have further implications, for instance on the use of police dogs to detect drugs and bombs.

He said: "Neither orcas nor any other animal were included in the 'We the people', when the Constitution was adopted."

It is not the first time that Tilikum has appeared in the media. In February 2010, the orca was in the spotlight when he drowned his trainer in front of the theme park audience.