Stories of police abuse abound

The report says the country's poorly-trained and often corrupt police force, under pressure to combat rising crime rates, increasingly see torture as an acceptable method to secure convictions.

But Mr Amorim told the BBC that the practice was not tolerated by the government.

Proof of this, he said, was that Brazil had invited a special UN envoy to help it find a solution to a problem the authorities readily acknowledge.

Mr Amorim said a series of measures have been approved to improve poor detention conditions, fight police corruption and eradicate torture - among them a dedicated phone number which inmates or their relatives could call to report mistreatment.

'Impunity'

The Brazilian Government in its report to the UN Committee against Torture admits that torture is a big problem and that perpetrators often go unpunished.

Conditions in the jails are appalling

Suspects, particularly those with criminal records, risk being mistreated during interrogations, it says, and police officers often resort to violence.

The government gives details of human rights abuses in the country's police cells, prisons and juvenile detention centres, which it says are overcrowded and often mismanaged.

Brazil has also acknowledged that the country's anti-torture law, passed four years ago, has had limited results.

No one has yet been convicted and only a few hundred cases have ever come to trial.

Amnesty International says this has created a climate of impunity which makes a mockery of Brazil's ratification of the UN convention against torture 11 years ago.