This African elephant has what are believed to be the biggest tusks among elephants at Kenya's Samburu National Reserve.

Illegal poaching of some 30,000 elephants a year for their ivory tusks threatens the animals with extinction.

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Most of the seized ivory tusks in Africa are derived from recently killed elephants, not from antique tusks, comprehensive forensics analysis revealed.

The finding indicates that the rising ivory trade is taking a toll on existing elephant populations.

What's more, the recent surge in elephant deaths in Africa may likely be connected.

"That puts to rest a speculation which has been at the back of everyone's mind," said conservation ecologist George Wittemyer of Colorado State University.

“It is really shocking that it’s all come from recently killed animals,” says study author Kevin Uno, a geochemist at Columbia University.

“This shows how serious the problem is, and how we need to continue to attack this problem from many different angles: enforcement, forensics, education.” Poaching has been soaring in the past decade.

A report about the new method was published online July 1 in Proceedings of the National Academy of Sciences.

Fisher studies mammoths and mastodons, and over several decades has developed techniques to interpret the life histories of those prehistoric pachyderms by analyzing growth layers within their tusks.

Almost all the world’s illegal ivory comes from elephants that have been recently killed, researchers say.