Socialist politicians have claimed they are part of a witch-hunt after the arrest of their official spokesman, Paulo Pedroso, on 15 charges of sexual abuse of minors following a phone-tapping operation by police.
The trial of a top TV presenter, a former ambassador and a leading children's health expert on similar charges is expected to start soon.
The country's Attorney-General denied that Socialist Party leader Eduardo Ferro Rodrigues was suspected of any involvement in the child abuse ring alleged to include senior members of the Portuguese establishment. Rodrigues, a government Minister until last year, had earlier revealed that his name was included in the documents which led to the arrest of his party spokesman.
However, the judge leading the investigation, Rui Teixeira, has told the Speaker of Portugal's parliament, Mota Amaral, that there are other paedophile cases allegedly involving politicians currently under investigation.
The scandal first erupted in February when a former pupil at a leading Lisbon children's home launched a legal action against a social worker nick-named 'Bibi', allegedly at the centre of a child-for-sex procurement ring involving leading politicians and media figures.
The case was brought after 20 years of complaints to the police by children at the home about systematic sexual abuse and beatings at the hands of carers failed to bring a single prosecution.
It is claimed that children from the home were picked out and then flown to the holiday homes of influential fig ures where they were repeatedly abused. A former Social Security Minister, Teresa Costa Macedo, backed their claims by saying that a paedophile ring operated from within the children's home. Other victims have since come forward following the shock arrest of Carlos Cruz, one of the country's top television entertainers.
The arrest of Pedroso is the first of a politician during the investigation. It follows the testimony of two 14-year-old boys who identified the 38-year-old divorc� from photographs and claimed that they were taken to a country home in Elvas, near the Spanish border, on several occasions during 1999 and 2000 while Pedroso was still a Minister.
The former Social Security Minister was remanded in custody at dawn on Thursday morning after 13 hours of interrogation, charged on 15 counts of sexual abuse.
The former Socialist leader and Prime Minister, Ant�nio Guterres, a close friend of Tony Blair, has promised to testify in Pedroso's favour.
The present Prime Minister, Jos� Manuel Dur�o Barroso, said: 'The judicial system in Portugal is completely independent. What I hope is that it does its job.'