The cluster during the early phase of the pandemic has been blamed for thousands of infections around the world.
Peter Kolba, who heads the VSV consumer association, said the four cases – involving an Austrian and three Germans – will test the ground for a further 1,000 people who have asked to be represented by the group after falling ill with Covid-19.
The outbreak in Ischgl in February and March is considered one of the earliest “super-spreader” events on the continent.
Mr Kolba said his association has been contacted by 6,000 people from 45 countries.
About 80% of those tested positive for Covid-19 after returning from Ischgl and at least 32 people from the resort cluster have died.
He accused authorities in the Paznaun Valley, where Ischgl is located, of being beholden to the interests of the local tourism industry.
Numerous infections allegedly occurred in cramped apres-ski bars where tourists often party the night away after a day on the slopes.
Mr Kolba also placed some of the blame on Austrian Chancellor Sebastian Kurz for declaring on March 13 that the valley would be placed under quarantine later that day, triggering the hasty departure of thousands of guests and seasonal workers.
“When it comes to managing the departure … Chancellor Kurz is probably the one who caused the chaos,” Mr Kolba told reporters in Vienna.
“What he did was reveal that something would happen and created an impossible situation for the police on site.”
He said authorities had enough information by March 7 to warn new arrivals about the virus but failed to do so.
When the government imposed a regional quarantine on the Paznaun Valley on March 13, some 10,000 foreign tourists were told to leave Austria but officials only collected contact details for 2,600, he said.
Mr Kolba urged Mr Kurz to consider convening a roundtable of resort visitors and authorities in the western state to discuss how to compensate people without going to trial.
He indicated a simple apology will not suffice.
“If someone is found in Tyrol today who says specifically what mistakes were made, if they apologise without ifs and buts, and then say how many millions will be set aside to compensate the tourists instead of building new cable cars, then that’s a good first step,” Mr Kolba said.
“But that would surprise me.”
Alexander Klauser, a lawyer for the VSV, said one of the four cases was submitted on Tuesday on behalf of relatives of a man who died as a result of Covid-19.
Two others are still suffering effects from the infection in spring, while a fourth had only a mild illness.
Mr Kolba said the plaintiffs are seeking damages of up to 100,000 euro (91,319) each from the Austrian government, which holds ultimate responsibility for enforcing health regulations.
