Finland began a so-called port state control inspection of the detained Eagle S tanker, which is being held after it reportedly ruptured undersea cables in late December.

In the latest step affecting the vessel, the Finnish Transport and Communications Agency Traficom is looking into whether the tanker fulfills requirements of maritime treaties, according to a statement on January 2. The routine operation could take a number of days, authorities said.

A subsea power link and four data cables were damaged December 25, after Eagle S sailed over them on the Gulf of Finland. Authorities found drag marks likely left by its anchor over a distance of “dozens of kilometers” on the bottom of the sea, and identified the ship as the culprit. 

The vessel, sailing under the Cook Islands flag, has been identified as member of the shadow fleet transporting Russian petroleum products, and is now detained at a port in southern Finland. It’s under investigation for aggravated criminal mischief and aggravated interference of communications. A travel ban was imposed on seven members of the ship’s crew on December 31, after they were identified as suspects in the criminal probe by the National Bureau of Investigation. 

It’s the third incident in just over a year in which a ship anchor has ruptured underwater infrastructure in the Baltic Sea, and Finnish President Alexander Stubb has said such frequency means the events “cannot all be a coincidence or an accident.”

Closer inspections on the damage to the EstLink 2 power cable are also underway, its operator Fingrid Oyj said in a separate statement on January 2. That will allow more detailed planning of repairs, Fingrid said. It has previously estimated the works could take as long as seven months. The operator also asked the Helsinki District Court to seize the vessel in order to cover damages to EstLink 2.

In November, a high-speed fiber optic cable in the Baltic Sea connecting Finland and Germany was severed by what was likely an external impact, and a nearby link between Lithuania and Sweden was also damaged, with authorities connecting Chinese bulk carrier Yi Peng 3 to the events. A year earlier, the anchor of Newnew Polar Bear, a Hong Kong-flagged ship, tore up at least two data cables and a gas pipeline, prompting the North Atlantic Treaty Organization to step up patrols.