Hong Kong (CNN) -- In one of the biggest busts of its kind in Hong Kong, customs authorities this week seized more than 1,100 ivory tusks, 13 rhino horns and five leopard pelts. The haul, found in a container shipped from Nigeria, is valued at more than $5.3 million.
On August 6, Hong Kong customs officials -- tipped off by their mainland Chinese counterparts -- detained "two suspicious containers" for inspection, according to a Hong Kong government press release. Authorities found the animal products "inside 21 sealed wooden crates at the rear of one of the containers."
Authorities have not made any arrests in this case so far.
Following this week's discovery, Hong Kong customs have now confiscated some eight tons of elephant ivory -- in at least four separate hauls -- within the past year. With a black market price of almost $3,000 a kilogram, its total worth could easily surpass the $20 million mark.
Customs officials in July opened a container originating from Togo to find 1,148 tusks valued at $2.2 million.
On April 30, airport customs officers zeroed in on a package labelled as "spare parts" originating from Burundi, transiting through Hong Kong and with Singapore as its final destination. Authorities discovered 113 ivory tusks valued at nearly $400,000.
In November 2012, Hong Kong authorities seized $1.4 million worth of smuggled ivory in a container from Tanzania. The 569 tusks were found buried under hundreds of bags of sunflower seeds.
And in a bust just one month earlier, customs officers detained two containers from Tanzania and Kenya that claimed to be ferrying scrap plastic. More than four tons of ivory -- some 1,200 ivory tusks -- were found. The haul, valued at $3.4 million, made for one of the biggest seizures of ivory tusk in the history of the Chinese territory.
Conservationists estimate that 25,000 elephants were killed for their ivory in 2011. Poaching levels have not been that high for more than 10 years. In many parts of the continent, murder rates now exceed population growth, putting elephants at risk of extinction.
The reason is simple, said Jeffrey Gettleman, East Africa Bureau Chief for the New York Times to CNN's Christiane Amanpour.
"It's the economic growth in Asia. And what's interesting is a lot of these economies are becoming more modern, more sophisticated, more advanced, like China, Vietnam, other parts of Asia, but they still adhere to traditional beliefs. And in many parts of Asia, ivory and rhino horn powder are valued for ceremonial purposes, for religious purposes, cultural purposes."
China is the world's number one market for ivory products, according to animal welfare groups. Hong Kong, the world's third largest port, serves as an easy entry point into and out of mainland China.
As China's citizens have grown in wealth, their demand for ivory -- often referred to as "white gold" in the country -- has also rocketed.
In fact, the fate of many of Africa's elephants lie in a small number of Chinese hands, said National Geographic's Bryan Christy to CNN's Amanpour.
"We have 35 registered carving factories in China. That's all -- 135 registered retail shops. Only 300 or 400 registered known carvers. It's a very small number of people imposing an incredible cost on Africa."
Since 2009, the number of large-scale seizures of ivory headed for Asia -- categorized as more than 800 kilograms per shipment -- has more than doubled according to a March 2013 report by CITES, the Convention on International Trade in Endangered Species. The number of incidents hit a record in 2011.
Under Hong Kong law, a person found guilty of trading endangered species for commercial purposes is liable to a maximum fine of $5 million and imprisonment for two years.