Counterfeit town-planning licenses and influential accomplices within different government departments were reportedly used to hook the town up to running water and electricity.
The mayor meanwhile insisted he did not "even know where these illegal buildings are", but said he was prepared to order the destruction of all the illicit structures, the newspaper reported.
Many of the apartments have already been sold and five are already occupied, according to the paper.
A preliminary investigation into the matter has revealed that most of the materials used in the construction were not up to standard.
The reinforced concrete, the cement and even the electrical wiring were not in line with any Naples standards, despite the fact that the city is located in an earthquake-prone area.
The head of the Italian Senate's environment commission has reportedly written to the country's interior minister to demand that all the illegal buildings be destroyed.
He has requested an in-depth investigation into links between the La Camorra mafia and the local politicians who stood by as the town was built.