Mr Di Rupo, who is also economics and telecommunications minister in the ruling centre-left coalition, said rumours circulating about him were "the most foolish and most insulting information".
He was named by De Standaard but it gave no proof, nor sources.
Public rallies have demanded an independent inquiry into organised paedophilia which, it is claimed, goes deep into the Belgian establishment. The country is concerned about events in August, when two girls who had been abducted and sexually abused were rescued and the bodies of four other young girls were found.
Yesterday Herman De Croo, chairman of the opposition VLD liberal party, urged the government to clear the air over reports that Mr Di Rupo was being investigated.
In a statement, the deputy prime minister said he was "a victim of a mix-up and confusion between events in my private life, which do nobody harm, and disgusting, outrageous acts which people want to attribute to me". He defended values he said he stood for as a politician. "In those values, my emotional life is a treasure which is only conceivable with responsible and consenting persons."
The Brussels prosecutor's office, responding to press reports of a investigation into links between politicians and young homosexual prostitutes, confirmed that police searched properties on Friday but no more information was given.Reuse content