The silver-mounted tusk, put up for auction last year, did not have the right documentation under wildlife protection laws, a police statement said.
A representative for the auction house pleaded guilty in London for selling the ivory, in contravention of an article in the Convention on International Trade in Endangered Species.
“The tusk in this case was mounted on silver but was basically a raw, unmodified elephant tusk and therefore should not have been offered for sale without the correct documentation,” said Rowena Roberts, wildlife officer for London’s Kensington and Chelsea borough.
“These laws were established to protect the world’s remaining elephants.” Christie’s stressed that it took the protection of endangered species seriously and had a training programme in place.
“Christie’s unequivocally condemns the slaughter of elephants for illegal ivory and will not sell modern ivory, or unworked tusks of any age,” a statement said.
“This was an isolated incident and we believe that the honourable response was to accept the charge as made.”
The 63-year-old owner of the ivory was charged with offering it for sale, police said.
Elephant numbers are in decline with 30,000 killed every year in Africa out of a population of between 450,000 and 500,000 to satisfy demand for ivory in Asia, where raw tusks sell for around $1,000 a kilo (2.2 pounds).