The recommendation was made by members of the UN subcommittee after a 10-day visit to Portugal between 1 and 11 May, during which it visited four cities and discussed the issue with the authorities and civil society.

Members of the group visited prisons and mental health centres in Lisbon, Coimbra, Porto and Sintra and met with the Ombudsman and representatives of the Government and civil society.

According to the information released, the experts also accompanied members of the National Mechanism for Preventing and Combatting Torture on visits to a juvenile detention centre and a prison.

The head of the UN delegation, Nora Sveaass, said it essential that this independent mechanism should have enough resources to ensure "a better structure and protection to prevent torture and ill-treatment."

This issue related to young people will be part of the report that will be delivered to the Portuguese authorities.

The group also called for more rehabilitation programmes and proposed that Portugal find alternatives to detention.

The delegation was made up of specialists Satyabhooshun Gupt Domah (Mauritius), Roberto Michel Fehér Pérez (Uruguay), Kosta Mitrovic (Serbia) and Margarete Osterfeld (Germany).

Portugal ratified the Optional Protocol to the United Nations Convention against Torture in 2013.

Experts look at how countries meet their obligations after this commitment, which include setting up a framework to obsevre and monitor the situation in each country.

Meanwhile, Amnesty International Portugal welcomed the visit of the United Nations Subcommittee on Prevention of Torture.

"We look forward to the final report and we ask the Portuguese Government for a speedy publication of it. We call for waiting no more than a year for the authorization of the ministry so that the content of a report from an international body on pressing human rights issues is released," said Amnesty International Portugal.

Amnesty also welcomed the focus given in the preliminary message released on Friday on the need for the Portuguese prison system to focus more on rehabilitation, in line with higher international human rights standards.