STOCKHOLM (AP) — Swedish authorities said Friday they need more information before deciding whether to reopen the case of a 1994 ferry sinking in the Baltic that killed 852 people, in one of Europe's deadliest peacetime disasters at sea.

A TV documentary aired Sept. 28 on the M/S Estonia includes video images from the wreck site showing a hole in the hull measuring 4 meters (13 feet) on the starboard side.

In 1997, Sweden, Estonia and Finland concluded in a report that the ferry sank after the bow door locks failed in a storm. The report flatly rejected the theory of a hole, which has long been the focus of speculation about a possible explosion on board, or collision with another vessel.

“In order to be able to further assess the relevance of the new film material and compare it with the 1997 report from the Joint Commission of Inquiry, more documents need to be collected and further analyses carried out,” the Swedish Accident Investigation Authority said Friday.

The authority also said it needs surveys of the seabed conditions at the site and to make analyses of the ship’s hull structure and materials “to assess the appearance of the holes in the ship’s hull.”

It added that investigators have been given the opportunity to review the unedited raw film material and have also inspected the ferry's bow visor in Sweden.

In 1995, the three countries agreed that the wreck is considered as a final place of rest for victims of the disaster, and must be respected. Some 758 bodies remain entombed on the car ferry, which rests 80 meters (265 feet) underwater.