"We have been holding Feisal [Ali] for interrogation since yesterday night," Assistant Police Commissioner Gustav Babile told The Anadolu Agency in a Tuesday phone interview.
"The suspect had been hiding from government organs for a long time," he said.
"We had intelligence from our Kenyan counterparts that led to his capture," asserted Babile, who heads up Interpol's Tanzania office.
A Kenyan national, Ali is wanted by the authorities in his country for trading in illegal wildlife trophies.
Interpol had issued a Red Notice for his arrest.
"That's all I can tell you for now," Babile said, adding that the authorities still needed more time to interrogate the suspect.
"We will be in a position to give more information after completing our investigation," he asserted.
Tanzanian Tourism Minister Lazaro Nyalandu welcomed the arrest.
"This is a positive result that we are starting to get after the establishment of a semi-autonomous Tanzania Wildlife Authority (TWA) to help the fight against poachers," he told AA.
"We plan to join hands with East African partner states to fight those responsible for destroying our national heritage," Nyalandu added. "We will use all state organs to unmask those responsible."
In October, Tanzania called for an international ban on trading in ivory and rhino products in hopes of curbing poaching.
China, Vietnam, Thailand, Japan and the Koreas are believed to be the leading markets for animal trophies.
Tanzania is currently home to some 70,000 jumbo elephants and only 123 remaining rhinos, whose numbers have dwindled due largely to illegal poaching activity.
In 1980, Tanzania was home to 3,795 rhinos – nearly a quarter of Africa's black rhinos at the time. Only one decade earlier, that number had stood at 65,000.