By Matt McGrath
Environment correspondent
Confiscated ivory from elephants killed much than 30 years agone has turned up successful caller raids, accidental scientists.
The tusks were erstwhile portion of a stockpile seized from poachers and held successful sealed containers by the authorities of Burundi.
In this study, researchers utilized DNA and c dating techniques to amusement that immoderate of that stored worldly is present successful the hands of smugglers.
The authorities of Burundi has not responded to a BBC petition for comment.
The authors accidental seizures should beryllium destroyed and not stored.
Between 2007 and 2016 immoderate 100,000 elephants were killed for their tusks successful antithetic parts of Africa.
The survey examined samples from 4 large seizures made by instrumentality enforcement officials betwixt 2017 and 2019.
Using techniques to measurement the beingness of an isotope called carbon-14, the researchers recovered that astir of the captured ivory was from elephants killed wrong the erstwhile 3 years.
However, ivory from 1 seizure was chiefly from elephants killed much than 30 years ago.
Markings connected these tusks indicated they came from a supposedly well-guarded stockpile held by the authorities of Burundi.
The commercialized successful ivory has been banned since 1987 successful Burundi, 1 of the world's poorest countries. In 2004 scientists from wildlife commercialized experts, Traffic International, examined the stores which comprised astir 84 tonnes, made up of 15,000 tusks. Customs seals were past affixed to the 7 containers holding the ivory.
However since 2015, a fig of seizures successful antithetic parts of the satellite person had markings showing Burundi arsenic the origin.
The BBC has approached Burundi's situation ministry for remark but has not had immoderate answers to our questions regarding the stockpile.
According to scientists, the authorities has until precocious claimed that their stores are secure.
"Those containers request to beryllium re-opened and the banal that's held determination needs to beryllium re-tested," said Prof Samuel Wasser from the University of Washington, an adept successful conservation biology and an writer of this caller study.
"Because the authorities are besides saying the weights of these containers haven't changed, does that mean that they are smuggling retired ivory and past getting caller ivory and simply replacing the old?"
"Well, if that's happening, that's truly bad," helium told BBC News.
The caller probe underlines the information that galore African countries proceed to clasp stockpiles of ivory that they person recovered from seizures since the commercialized successful ivory became illegal.
Some experts question wherefore they are choosing to bash this alternatively than destroying the stocks, fixed that planetary agreements prohibit the merchantability of ivory recovered from poaching.
Stockpiles are besides susceptible to theft arsenic happened successful Mozambique successful 2016.
Researchers person besides seen grounds of seized ivory coming backmost into the amerciable marketplace by dubious means.
"When we illustration these seized tusks we instrumentality a small quadrate retired of the bottommost of them, and determination has been astatine slightest 1 seizure wherever we saw that our squares had been chopped out, meaning that this was ivory that we had antecedently sampled and was present being re-smuggled," Prof Wasser explained.
However different groups accidental that stocks tin beryllium legitimately kept for research, acquisition oregon recognition purposes.
The Elephant Protection Initiative (EPI) is presently supporting 15 African countries to unafraid their stockpiles of ivory but is besides helping others to destruct their stockpiles.
"Ivory doesn't person immoderate commercialized worth and that is improbable to change," said John Scanlon, from the EPI.
"It's up to each state to determine connected the champion enactment for it, and each state volition beryllium guided by its ain home considerations."
"If it is stored, it needs to beryllium done securely and beryllium reported. If it is destroyed, it needs to beryllium accounted for, and forensic samples should beryllium taken to place the root of the ivory."
The probe has been published successful the Proceedings of the National Academy of Sciences.
Follow Matt connected Twitter @mattmcgrathbbc.