LONDON -- Six suspects accused of orchestrating one of South Africa's largest rhino horn trafficking operations appeared in court Tuesday following a 7-year investigation that uncovered a scheme involving 964 rhino horns destined for illegal markets in Southeast Asia, authorities said.

A leading conservationist in South Africa, charged with smuggling rhino horns worth $14m (£10m), has insisted he has "nothing to hide". In a statement, John Hume, the former owner of what is thought to be the world's largest rhino farm, denied allegations that he trafficked the horns from South Africa to South East Asia.