The UN's leading human rights advocate says a new Danish immigration measure is "very likely" to cause harm.
UN human rights chief Michelle Bachelet has slammed Denmark's plan to send some foreign criminals to a remote island.
Last week, the Scandinavian nation announced it would use Lindholm Island to house criminals whose sentence of deportation cannot be carried out because they risk torture or execution in their home country.
Ms Bachelet expressed concerns about the plan on Wednesday, saying it is "very likely" to cause harm.
"We have seen the negative impact of such policies of isolation and should not replicate these policies," the former Chilean president said.
"Depriving [these people] of their liberty, isolating them and stigmatising them will only increase their vulnerability.
"Sometimes there are difficulties encountered in returning migrants to their countries of origin when they're not accepted as refugees. But this should be addressed in a safe and humane way."
Ms Bachelet also voiced concern around the language used in Denmark's immigration debate, after Immigration Minister Inger Stojberg labelled these individuals "unwanted".
"[This language] serves to increase stigma and hate, fuelling divisions and xenophobia," she said.
'NO reason to be in Denmark'
The new arrangement was part of an agreement between Denmark's conservative coalition government and anti-immigration party the Danish People's Party (DF).
On Friday, Finance Minister Kristian Jensen said "there will be a ferry service to and from the island, but the ferry will not operate around the clock, and they must stay at the departure centre at night".
"That way we will be better able to monitor where they are," he said.
After the announcement, DF posted a video on its Twitter account of a dark-skinned man in what appears to be Islamic attire being sent to the island.
"Deported, criminal foreigners have NO reason to be in Denmark. Until we can get rid of them, we will move them to the island of Lindholm," the tweet read.
"They will be obliged to stay at the new deportation centre at night and there will be police around the clock. Great!"
But leader of the environmentalist Alternative Party Uffe Elbaek said the policy showed a "humanitarian collapse" in Danish politics.
Lindholm Island is currently used by the Technical University of Denmark's (DTU) Veterinary Institute, which carries out research into viruses affecting cattle and swine.