The operation was focused on bribery and rigging of contracts in the crematorium and archaeology business in favour of the Zagaria clan.
One of those arrested was Naples' top archaeology official while another was an ex-mayor of Pompeii, reports said.
A construction entrepreneur was alleged to head the corruption network.
The Casalesi cartel is seen as the strongest branch of the Camorra, the formidable organised crime syndicate in the Naples area.
On Tuesday, prosecutors warned that the cartel had taken control of farm and food businesses in the region too, particularly sales of buffalo mozzarella.
Read more on organised crime in Italy:
Italy's financial crime police spread their net wide in Wednesday's operation to include local officials, civil servants, accountants and university professors, local media said. Adele Campanelli, the head of Naples' architecture and fine arts department, was placed under house arrest, according to several reports.
Police are investigating 18 contracts awarded since 2013, such as the construction of a museum close to the Roman amphitheatre at Alife and a new crematorium in modern Pompeii.
Police in Naples have arrested 69 people, including political figures and businessmen, in raids targeting Naples' notorious Casalesi cartel.