The Estonia sank in a storm on September 28th, 1994, in the Baltic Sea en route from Stockholm to the Estonian capital Tallinn. Only 137 people out of the 989 passengers and crew members on board survived.
The Tallinn administrative court made its decision on Thursday regarding the request for a more thorough investigation submitted in 2016 by survivors and relatives of the victims, according to the Baltic news agency BNS.
There were 501 Swedish nationals among the dead and 285 Estonians.
Although the request had been submitted to the prime minister, to date only the justice ministry had responded late last year, saying the matter was outside its competence.
The relatives and survivors had petitioned the premier as head of government, as only the entire cabinet of ministers has the competence to decide whether to launch a new inquiry.
The cabinet will have 60 days to respond to the request once the ruling enters into force. But it has the option until November 25th of appealing the decision.
Despite calls from relatives of some of the victims for the wreck to be raised and the bodies recovered, an agreement between Estonia, Finland and Sweden designated it a marine grave and left it untouched.
A 1997 investigation conducted by the three countries concluded that the sea flooded into the car deck because of a problem with the door on the ferry.
The ship’s builder has paid out 130 million euros in compensation to survivors and to relatives of the dead.
Last month, survivors and relatives again called for a fresh inquiry into what happened, at memorial ceremonies marking the 25th anniversary of the disaster.
They claim the original investigation was not thorough enough and that the resulting conclusions contained contradictions. They would also like the wreck to be raised.