A United Nations conference has given Swaziland the green light to export some of its white rhinos and bring in trophy hunters to shoot the animals.
Trophy hunters pay tens of thousands of pounds to shoot the animals
The motion was passed by the Convention on International Trade in Endangered Species, which is meeting in Bangkok.
It follows last week's lifting of a ban on hunting the rarer black rhino in Namibia and South Africa.
Swaziland claims money raised from exports of live animals or trophy hunts will be used for rhino conservation.
The Swaziland proposal to down-list its white rhinos from Appendix I, which bans all trade, to Appendix II, which allows limited trade, was passed by a large majority, with 88 in favour and 15 against.
The EU, with a crucial total of 25 votes, supported the proposal.
Trophy hunters - mostly American and European - pay tens of thousands of dollars to shoot animals such as rhinos, with the price tag pegged to the rarity of the species.
Swaziland has 61 white rhinos - the second largest land mammal after the elephant - and space is an issue in the small developing country of one million people and rising.
"Our space is limited and our white rhino populations are reaching ecological carrying capacity for the species," Swazi delegate James Reilly said.
Mr Reilly claimed that only one trophy hunt would be allowed every two years at most, and problem animals would be targeted. "Our preferred option is live removal," said Mr Reilly.
However, some lobby groups do not support the move. "This proposal is disastrous for a species which is still severely threatened in much of its range," said Jenny Hawley of the International Fund for Animal Welfare (Ifaw).
"It also sends a dangerous message that commercial interests outweigh the long-term survival of the species.
CITES - DEGREES OF PROTECTION
Appendix I: controls species whose existence is so threatened that trade is banned. Covers some 1,000 plants and animals, eg great apes
Appendix II: Allows controlled trade, under a system of permits. Covers 4,100 animal species and 28,000 plants
Appendix III: Contains 290 species that are protected in at least one country.
"Although Swaziland claims to need to trade its rhinos to pay for conservation of the species, the Swazi king was recently reported to be building new palaces for each of his 13 wives."
White rhinos have been hunted in South Africa legally for more than three decades. Pushed to the brink of extinction a century ago, there are now thought to be several thousand individuals.
Rhinos are still targeted by poachers in Africa and Asia for their horns, which fetch high prices in the Middle East, where they are valued for dagger handles, and in East Asia, where they are used in traditional medicines.
The signatories to Cites are meeting in the Thai capital for their 12-day biennial summit which ends on Thursday.
Last week, the gathering approved a proposal for Namibia and South Africa to each kill and export five black rhinoceros per year.
Again, the countries said the money raised from the trophy sales would help pay for improved conservation efforts.