The stunning beach known as Cimetero di Procida was featured in the Academy Award-winning film, Il Postino (The Postman), which was released in 1994.
Local media said sample testing by Italy's environmental protection agency had found high levels of E.Coli and fecal bacteria, believed to be due to inadequate drainage of human waste.
Samples taken by officials on August 12th revealed 1445 units of E.Coli for every 100 millilitres of water, three times above the acceptable limit for swimming.
Officials from the protection agency were due to return to the beach on Tuesday to take fresh samples. They were also expected to check the beach of Ciraccio, which was inundated by polluted water when a pipe exploded at the weekend.
Media reports said there were also signs of pollution at the beach of Perrone at Casamicciola Terme, while five other beaches between Naples and Sorrento had been closed to swimmers.
Beach bans at the height of the summer season are particularly embarrassing as tourism is critical for the survival of Procida and other popular spots on the coast south of Naples. Tests in Sorrento had also revealed unacceptable pollution levels in the water, experts said.
The Postman is a fictional story of a postman and a poet who shares his love of poetry with him. The charming film was nominated for five Academy Awards in 1995 and scored one Oscar .