It is illegal to own or carry government trophies (wildlife parts and products) without a permit from the Tanzania Wildlife Division.
For visitors who have purchased trophies from other countries, they are required to have an import permit from the Tanzania Wildlife Division, a process which may take a bit of time and definitely not convenient for someone on holiday. In other words, tourists carrying trophies / wildlife products are advised to post the trophies bought from other countries directly to their home countries before coming to Tanzania.
A complete regulation on import and export of trophies is hereby given in the below download.
Government trophies include animal skins, bones, seashells, plants or any other wildlife product / object / souvenir.
While we know most if not all visitors take conservation and its regulations very seriously, it is unfortunate some individuals end up breaching the law probably out of ignorance.