Rome, November 8 - Italy's national office against racial discrimination on Thursday opened an investigation into racial insults directed at Italian writer and anti-mafia campaigner Roberto Saviano. The probe comes after the Neapolitan author of the bestselling title Gomorrah on Wednesday issued a tweet saying that the neo-Nazi website Stormfront had published the phrase ''The Jew Saviano wants to nominate a negro as the mayor of Castelvolturno'' in reference to his recent proposal that Ivan Sagnet, from Cameroon, stand for mayor in the southern Campania town whose council was dissolved by the government earlier this year due to infiltration by the local Camorra mafia. A year ago the same website published a list of ''faces to eliminate'', which included Saviano. The writer has Jewish origins on his mother's side. The anti-discrimination office has described the latest episode as ''shameful'' and said it has asked the postal police to obscure the site. It will also file a report with the state prosecutor's office.