In the latest diving incident, the 30-year-old Kiwi tourist broke away from his friends and dived into the fountain.
Fully clothed in jeans, a long-sleeved top, socks and shoes, the man swam back and forth across the fountain’s basin, ignoring police demands to get out of the water.
He was eventually fined €500 ($994) and banned from returning to the site.
Video of the incident went viral in Italy, provoking calls for higher fines and even jail terms to deter badly behaved tourists and to safeguard the fountain.
One woman posted on Facebook that “€500 is small change. If it was €5000 they would think about it for a while.”
The fountain is patrolled by police 24 hours a day, while barriers have been erected to control the flow of visitors. Since February, tourists have had to pay a fee of €2 ($3.98) to reach the edge of the fountain’s basin.
Roberto Gualtieri, the Mayor of Rome, was not available for comment but he has previously proclaimed the ticketing system as a success.
Rome city council is also increasing the number of video surveillance cameras in more than 50 public squares including the one surrounding the Trevi Fountain, a spokesman said.
The New Zealander’s dive is the latest incident involving tourists behaving badly at the Trevi Fountain.
Last year, a London-based tourist - also from New Zealand - was stopped by police and fined for wading into the fountain on a Saturday night. He was also banned from returning to the site.
Completed in 1762, the Trevi Fountain occupies one side of Palazzo Poli in the historic centre of the Italian capital. The water that feeds the fountain comes from an ancient Roman aqueduct, the Acqua Vergine.
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