More than 6,000 tourists from 45 countries, including Germany, the UK and the US, allegedly contracted the virus while holidaying in the western Austrian province of Tyrol, the majority of them in Ischgl, a small ski resort popular for its apres-ski partying.
The public prosecutor's office in the regional capital of Innsbruck confirmed to AFP that they had narrowed their investigation to four people after a thorough initial probe and a review of more than 10,000 pages of evidence.
The prosecutor's office declined to identify the suspects.
“In particular the implementation of a decree in regards to traffic restrictions in Ischgl as well as the quarantine of Paznauntal valley is being probed more closely,” Hansjoerg Mayr from the public prosecutors' office said.
Tourists have accused local authorities of failing to inform them of the outbreak at the resorts in a timely fashion, as well as a panicked evacuation during which many had to cram onto public transport alongside sneezing and coughing fellow visitors.
Austrian public broadcaster ORF, citing an anonymous source, said that the four people under investigation were Ischgl's mayor Werner Kurz and Markus Maass, the head of Landeck district — which administers Ischgl — along with two other officials.
They are being investigated for having wilfully or negligently endangered people through a contagious disease, according to ORF.
Several days after authorities were made aware of infections in one of Ischgl's tightly packed bars, Austrian Chancellor Sebastian Kurz announced on March 13 that the narrow valley would be put under lockdown, and that thousands of tourists would have an hour to evacuate.
Panic ensued, and tourists reported that the 30-kilometre (18-mile) ride to the district's capital took up to seven hours on crammed buses as authorities demanded they sign forms promising to return to their respective homes without making any detours.
No one, however, was tested for the virus, and thousands of tourists now believe that they helped spread the disease across Europe at a time when the World Health Organization was yet to declare the coronavirus a pandemic.
Mayr said his office has yet to decide whether charges will be taken to the courts.
Officials in Landeck district referred AFP to the regional government, which declined to confirm the names of those under investigation but said it would support “all investigations as much as possible”.
Ischgl's mayor did not reply to a request for comment.