Massimiliano Fedriga, a member of Italy’s League party, has been placed under observation, La Repubblica reports.

In his role as president of the north-eastern region of Friuli-Venezia Giulia, the politician opposed the ‘Lorenzin law’, which made vaccination of schoolchildren against a number of diseases, including chicken pox, polio and measles mandatory.

Under the legislation, parents can be fined up to €500 if they send unvaccinated children to school.

Fedriga told Euronews he had “always been a supporter of vaccines”.

“I am not against vaccines, on the contrary, I am in favour of a stronger alliance with the families,” he said.

Italian microbiologist Roberto Burioni warned against not vaccinating children.

“Unfortunately, chicken pox is not only very contagious (and dangerous) but is even transmitted by patients before the onset of symptoms,” he said on Facebook.

The number of measles cases in Italy has surged, according to the World Health Organisation.