From a report titled “Vanishing Point: Criminality, Corruption and the Devastation of Tanzania’s Elephants,” by the Environmental Investigation Agency, as explained in the New York Times:
The organization has traced bribery and collusion in ivory smuggling to politicians from Tanzania’s governing party, led by President Jakaya Kikwete. When he took office in 2005, there were about 142,000 elephants in Tanzania. By the time Mr. Kikwete is to step down next year, the population is expected to have declined to just 55,000. Tanzania currently bans all domestic and international trade in ivory.”
The NYT article also alleges,
When President Xi Jinping of China and his entourage of government officials and business leaders arrived in Tanzania in March 2013 … members of the Chinese delegation used Mr. Xi’s visit as an opportunity to procure so much illegal ivory that local prices doubled to about $318 a pound.