Amnesty International has criticised Cyprus for treating migrants and asylum-seekers as "criminals" by locking them up.
The London-based human rights watchdog said in a report released on Tuesday the eastern Mediterranean island should review its legislation and bring it into line with international standards.
"Irregular migrants treated as criminals in Cyprus," said the headline of the report issued less than two weeks before Cyprus takes over the rotating presidency of the European Union.
"Hundreds of the men and women who flee each year to Cyprus in search of refuge and asylum from war, persecution and poverty are locked away by the island's authorities in breach of their international obligations," it said.
"Detention should not be a tool for regulating migration," it said in the report entitled "Punishment without a crime: Detention of migrants and asylum-seekers in Cyprus".
Amnesty said that authorities in Cyprus were violating the laws of the European Union, which the country joined as full member in 2004.
"Cyprus authorities are wilfully violating International and European Union law when they detain irregular migrants without examining alternative measures and demonstrating that their detention is indeed necessary," said Amnesty's Giorgos Kosmopoulos.
"Instead it is routine to deprive them of their liberty, for months or years, not because they have committed some crime but simply to effect their deportation and even in cases where their deportation is impossible."
Amnesty also criticised conditions in detention centres on the island, saying they were overcrowded and unhygienic.
It also spoke of the case of a Sierra Leonean identified only by the initial, O, who was detained in Cyprus and later deported, even after he took his case to the Supreme Court which issued a verdict in his favour.
The court had ordered his release from detention but "before he left the court premises he was arrested and detained once again", said Amnesty.
"The new arrest order was dated one day before the Supreme Court judgement was issued," it said.
"O was deported to Sierra Leone in February after having spent in total more than four months in detention in Cyprus," it added.