Coronavirus cases may have already been present in January or even earlier in northern Italy and the Lombardy region, Stefano Merler, a researcher from the Bruno Kessler Foundation, a top research institute in Italy, told a media briefing on Friday.

In Lombardy "there are hundreds of cases that had symptoms before February," he said at the media briefing. 

"I think there have been multiple introductions of the virus, which explains why we already had hundreds of cases by February 20," Merler said.

The first official COVID-19 case in Italy was reported on February 20. To date, Italy has world's third largest infections with nearly 190,000 cases after the U.S. and Spain.

A total of  25,549 have died in Italy, the second highest death toll in the world after the United States. 

Italy has been studying how the outbreak started in the country since "patient number 1" – a 38-year-old Unilever worker who had received treatment at the municipal hospital in Codogno.

According to local media, a scientific study in March, which Merler himself had taken part in, revealed that the virus was already in circulation at the beginning of January.

"In Codogno, the first reported cases developed symptoms towards the end of January 2020," said the study, quoted by local media.

While Italy is reported to have eased its lockdown, which had been put in place since early March, scientist warned caution.

Also attending the briefing on Friday, Silvio Brusaferro, the president of Italy's Higher Institute of Health, said despite the improvement Italy has seen, the country still needs to be mindful with reopening due to varying situations across the country.