- Video report by ITV News Correspondent John Ray
A Chinese grandmother who was at the centre of Tanzania's illegal ivory trade could spend up to 17 years in prison for her role in a smuggling operation between east Africa and China.
At first glance, Yang Feng Glan looks like an unlikely candidate to be the mastermind behind the international black market.
But authorities in the African nation say the Chinese national, who is in her sixties, was behind a smuggling syndicate worth £1.7m, transporting the animal products out of Tanzania.
It is believed to be the biggest ever haul of the animal product ever seized.
Yang's smuggling enterprise has earned her a nickname; The Ivory Queen.
The grandmother was convicted alongside two others.
The prosecution of Yang is significant, it is rare for a smuggling kingpin to be brought before the courts.
- What do we know about the Ivory Queen?
The so-called Ivory Queen originally hails from Beijing and reportedly first visited Tanzania in the 1970s.
Using a Chinese restaurant as a cover, Yang set up an international supply chain for ivory, transporting it more than 5,000 miles to her country of origin.
China has a huge market for illegally acquired ivory, despite authorities recently bringing in a ban on the product.
Working with a Tanzanian man, Yang is said to have buried tusks belonging to hundreds of animals in the gardens of two homes she had acquired.
Once the valuable materials had been measured and priced, they would be shipped out of the country and sold.
Authorities claim Yang used death threats to keep a grip over people, enabling her to continue running the international smuggling ring.
Following a high-speed car chase in 2015, Yang was arrested and charged with smuggling ivory worth £1.7 million between 2000 and 2014, although investigators believe this may only be the tip of the iceberg.
It is believed that Yang's role in the illegal ivory trade stretches back as far as the 1980s.
Her arrest was hailed a "breakthrough" in the international smuggling battle.
Whilst it is not unusual for people to be detained for the role, it is rare for those people to be the masterminds behind the businesses, more often they are simply foot soldiers working lower down the chain.
- Why is this conviction important?
Firstly, the rarity of bringing a leader of a smuggling ring to justice is a key step in the prevention of ivory smuggling.
Tanzania has previously been called the epicentre of the word's illegal ivory trade. This prosecution shows attitudes in the country are beginning to change.
Figures show elephant numbers there have dropped to just 43,330 from 110,000 in 2009 and 350,000 when the country became independent in 1961. Conservationists hope that further damage to the country's population numbers can be stopped.
Demand for the material in China has been blamed for the fall in elephant numbers, and Tanzanian authorities have long been accused of turning a blind eye to ivory kingpins, especially those linked to the large and influential Chinese community there.
Beijing has announced a crackdown on ivory products, earlier this year bringing in a total ban.
Internationally, the tide is turning on ivory trading.
In 2018, the British Government announced a ban, stating it would be "one of the world's toughest". As well as the lives of thousands of elephants, the brutal trade has led to the deaths of those working to stop it. In 2017 a prominent conservation worker for the stopping of the trade, Wayne Lotter, was assassinated as he was traveling through Dar es Saalam.
- How has Yang been punished and what will happen next?
Yang could spend up to 17 years behind bars for her role in the operation.
Her sentence will be reduced to 15 years if she pays a fine, equal to double the amount she made through the smuggling enterprise.
Yang has been convicted on the same charges as two other individuals thought to be key to the smuggling gang.
All three defendants have lodged an appeal against the ruling, local media reports.
Tanzania's Director of Public Prosecutions, Biswalo Mganga, told reporters: "15 years in custody is not a joke." He added that those convicted will have their assets seized, and that the conviction is "not a small issue."
Setting out the stance of the government, Mr Mganga said that people who come to Tanzania to exploit its natural resources will be prosecuted, regardless of their wealth or status.
Nehemia Nkoko, the advocate representing Yang, told ITV News that he is "not satisfied" with the ruling. He claimed that the court did not take into account the full range of evidence, nor did it see the ivory that Yang is alleged to have smuggled.
The PAMS Foundation, who Wayne Lotter worked for before his death, said in a statement on social media: "This is a great day for Tanzania."
Speaking to reporters outside the court on behalf of PAMS, Krissie Clark said: "I think [the ruling] is of huge significance because it shows that nobody is above the law. Tanzania is taking it seriously, it's as if an attack on Tanzania's wildlife is seen as an attack on Tanzania. I think it's testament to that the government is going to take it seriously".
She urged people who are involved in poaching to stay away from Tanzania.