The coronavirus appears to have been circulating in Italy since as early as September 2019, signaling that covert 19 might have spread beyond China months earlier than previously thought.

The World Health Organization has said the disease was unknown before the outbreak was first reported in Wuhan in December, and Italy's first covert 19 patient was detected on February 21 in a town outside Milan.

But the cancer institute looked at past lung cancer screenings and found that 12% of volunteers in a screening trial had developed coronavirus antibodies between September 2019 and March 2020 and well before February.

A further specific antibodies test was carried out by the University of CNF.

The same research, a co author of the study, told Reuters that it showed four cases dated back to the first week of October were also positive for antibodies neutralizing the virus, meaning they had got infected in September.

He also said that it showed the virus could remain in a population with a lowly fallacy rate, only to surge again later.

Italian researchers had previously told Reuters in March that they reported are higher than usual number of cases of severe pneumonia and flu in Lombardy in the last quarter of 2019, another sign that the new coronavirus might have circulated earlier than previously thought.