All 242 people onboard an Air India flight to Rome were ordered to quarantine with 30 passengers testing positive for Covid-19.
Two staff members also contracted the virus – the pilot and senior flight attendant.
The plane had departed from Delhi with a stop in Amritsar.
Italy has now imposed new rules that all travellers from India must undergo quarantine for 10 days.
The high number of positive cases is despite mandatory pre-travel Covid tests required..
It once again raises questions about the quality of Covid testing carried out in Indian labs, with similar incidences of high rates of positive cases on international flights out of the country.
Recently there were 52 cases detected on a Vistara flight from Delhi to Hong Kong.
Italy requires passengers to provide negative test results before departure.
Numerous countries have imposed strict quarantine on travellers coming from India and many have banned direct flights.
Australia has taken the strongest action, even banning its own citizens from returning home if they have been in India recently.