The Italian Swimming Federation (FIN) said world champions Simona Quadarella and Gabriele Detti were among those to have returned a positive test for COVID-19 at the camp in Livigno.

Olympic gold medallist and multiple world champion Federica Pellegrini had already been in isolation after testing positive, which forced her to withdraw from the International Swimming League. 

The training camp in Livigno, located in Lombardy, among the Italian regions which are set to enforce tougher restrictions to combat a second wave of COVID-19, began on October 11 and was due to end on November 5.

It has been put on hold and the team placed into quarantine following the positive tests, the FIN said.

At least 13 Italian swimmers have tested positive, but the FIN said all of the athletes in Livigno were asymptomatic.

Federico Burdisso, Martina Rita Caramignoli, Marco De Tullio, Stefano Di Cola, Sara Gailli, Edoardo Giorgetti, Matteo Lamberti, Alessio Proietti Colonna, Simone Sabbioni and Alice Mizzau are the others to have tested positive.

The suspension of the camp deals a blow to the Italian swimming team's preparations for the Tokyo 2020 Olympic Games, which have been moved to 2021 because of the coronavirus pandemic.

Italy confirmed another 10,874 cases of coronavirus yesterday, bringing its official reported tally to more than 434,000.

The European country was one of the worst-hit nations when the COVID-19 pandemic hit.