Eagle S is accused of deliberately dragging its anchor on the seabed to damage communication cables. The main suspects are the ship's captain, first mate and helmsman. They are being prosecuted for sabotage.
The ship is flagged in the Cook Islands in the Pacific. But Finnish authorities believe it is part of the Russian so-called shadow fleet, which has been established with more or less dubious methods to circumvent Western sanctions.
It was at the end of December last year that the oil-loaded ship is suspected of having dragged its anchor on the seabed and damaged several important underwater cables between Finland and Estonia.
Eagle S was then detained for two months for investigation in Finland. But then the ship was released. It is not immediately clear whether the accused are still in Finland.