DAR ES SALAAM, Tanzania — A Tanzanian court on Tuesday sentenced a Chinese businesswoman known as the “Ivory Queen” to 15 years in prison for smuggling the tusks of more than 350 elephants to Asia — a major victory in the effort to stamp out poaching in Africa.

The businesswoman, Yang Feng Glan, was charged in October 2015 and accused of smuggling $5.6 million worth of ivory, said to be 860 pieces between 2000 and 2004. She denied the charges.

Police sources said Ms. Yang, 69, had lived in Tanzania since the 1970s and was secretary general of the China-Africa Business Council of Tanzania. She also owns a popular Chinese restaurant in Dar es Salaam, the Tanzanian capital, and speaks Swahili.

Ms. Yang and two Tanzanian men — Salivius Matembo and Manase Philemon — were convicted of leading an organized criminal gang and sentenced to 15 years in prison.