AN ALLEGED people smuggler accused of organising a boat that sank with the loss of more than 350 lives is fighting his extradition to Australia.

Iraq-born Maythem Radhi is sought by the Australian Government over the notorious SIEV X boat, which sank in 2001 on its way from Indonesia to Australia.

His extradition was ordered in March but his legal team is appealing against the decision in the High Court in Auckland.

Mr Radhi, who was found living in South Auckland last year, was allegedly one of the key organisers of the boat later known as the SIEV (Suspected Illegal Entry Vessel) X.

The boat carrying 421 asylum seekers sank in international waters south of Indonesia on October 18, 2001, en route to Christmas Island. Officials estimated 146 children, 142 women and 65 men drowned when the fishing boat sank.

For Mr Radhi to be extradited to Australia the Crown has to show there was a comparable offence in New Zealand law that he had broken.