Tanzania has banned wildlife exports after about 130 animals and birds - including giraffes and vultures - were smuggled out of the country.
The wildlife - worth $110,000 (£66,700) - was flown out in a cargo plane from Tanzania's second airport last year.
Prime Minister Mizengo Pinda said the ban would stay in place until investigations into the theft ended.
The ban would affect businesses licensed to sell animals to zoos around the world, correspondents say.
Police said the animals and birds were flown out in a Qatari-registered plane from Tanzania's second airport, Kilimanjaro International Airport, which styles itself as "the gateway to Africa's wildlife heritage".
The stolen wildlife included four giraffes, 68 gazelles, two impalas, four ground hornbills and two lappet-faced vultures, police said.
The BBC's Tulanana Bohela in Tanzania's main city of Dar es Salaam says the theft took place last year, but police began investigating only a few months ago following an expose by the country's Guardian newspaper.
The opposition has been pushing for prosecutions, alleging a crime syndicate - including government officials and businessmen - was involved in the theft, our reporter says.
After MPs questioned him in parliament over the theft, Mr Pinda announced a ban on all exports of wildlife.
He said it would stay in place until the investigation was concluded and a review done into whether wildlife exports benefited Tanzania.
Our correspondent says Mr Pinda appeared to be trying to appease the public, which has been angered by the theft.
Many people suspect such crimes take place often, but rarely come to light, she says.
They support the ban, believing Tanzania should look after its animals, but it is likely to be opposed by the private sector as it will affect about 180 companies licensed to export wildlife, our reporter says.
They sell animals to zoos in the US, Europe and Asia.
Tanzania has some of the world's biggest game parks, including Serengeti and Selous, which are popular with tourists.