“The results of the international investigation commission are subject to strong criticism,” Estonian state prosecutor Margus Kurm told reporters.
“There is no comprehensive analysis in the final report about what caused the strong bangs or strikes that many survivors testified to having heard,” Kurm said.
According to the official report into the accident, drawn up by a team of investigators from Estonia, Sweden and Finland and published in 1997, the Estonia sank in stormy weather on the Baltic Sea because of poor construction of the locks on the bow visor.
Only 137 of the 989 passengers and crew on board survived.
The official investigation results have been questioned by relatives of the dead, shipping experts and politicians, many of whom claim the ship sank after an explosion on board.
Thursday’s criticism from the Estonian government commission was the highest level sign that the 1997 report was flawed.
“The three-country commission did not use all the possibilities to determine if an explosion occurred in the area of the visor attachments,” Kurm said.
“On the basis of the current evidence, it is hard to disprove the alternative theories about the reasons for the disaster,” he added.
In March last year, Estonia and Sweden launched new probes into the tragedy, to try to determine, in particular, if military equipment was being transported on the ferry when it sank.
It has been established that Swedish intelligence transported military equipment on board the Estonia at least twice prior to the ferry sinking.
Kurm said on Thursday that the Estonian government commission was unable to establish whether the ferry was transporting military equipment on its last tragic sailing.
Kurm also slammed the 1997 report for not adequately addressing the issue of whether there may have been a hole in the bottom part of the hull, possibly caused by an explosion.
“The bottom part of the hull was neither examined nor filmed to the fullest possible extent,” Kurm said.
In another damaging assessment about the three-country investigation, the new Estonian probe said the first probe did not establish how water was able to fill the lower decks of the ferry so quickly.
“Such quick filling of the lower decks with water has not been explained in the final report,” Kurm said.
Estonian Justice Minister Rein Lang suggested launching a new probe into the accident.
“It is up to the three countries involved – Sweden, Finland and Estonia – to decide whether a new international probe is required,” he said.
“Meanwhile, the Estonian government commission will continue work on the weak points in the international findings.”
Relatives of some of the 852 people who died when the Estonia sank 11 years ago in September called for a new inquiry into the cause of the tragedy, alleging cover-ups and false evidence in the original probe.