The official word on the M/S Estonia - which sank off Finland en route from Tallinn to Stockholm in 1994, taking 852 lives, was that the visor bow door had failed in rough seas, opening the ship to the waters that eventually sank it.
Despite the pronouncement from Stockholm, conspiracy theories have abounded - some speculating that the ship was being used to transport Russian military intelligence via Estonia through Sweden and onwards to the United States or UK. According to the most popular theory, as espoused in German journalist Jutta Rabe's 2003 film Baltic Storm (which sucked, by the way), an explosion onboard caused the ship to sink.
Adding more fuel to the fire, a Swedish customs officer in 2004 announced that yes, the ship had been used to smuggle Russian military secrets out of Estonia. This prompted Tallinn to set up its own investigation which confirmed the officer's account and accuses the Swedes of stonewalling their investigation in a report disclosed last week.
Now, as Sweden's The Local reported this week, some of Estonia's cabinet ministers didn't want to disclose the report because they felt it was so controversial.
Somehow, I wonder if this story will be a controversy that never dies, like the assasination of President John F. Kennedy in 1963 in the US. We too had a questionable official report, conflicting testimony from eyewitnesses, suspicious actions from involved governments, and high-profile films made about conspiracy theories. But that mystery has never been solved - and it's likely that this one won't be either.