Finland's National Bureau of Investigation (NBI) said on Tuesday that an anchor was raised from the seabed which is likely to have damaged the Balticconnector pipeline between Estonia and Finland earlier this month.
The NBI pulled a heavy object to the surface on Tuesday morning that turned out to be an anchor, it said at a press conference this evening.
General Head of Investigation Detective Superintendent Risto Lohi said a 1.5 to 4-meter-wide trail can be seen on the sea bed leading to the point of damage in the gas pipeline.
In the distance of a few meters from the gas pipeline damage point, there was an anchor, which is believed to have caused the wide dragging trail and the damage itself.
"Early this morning the anchor was lifted up. There are traces in it which indicate that it has been in contact with the gas pipeline," Lohi said.
From the finding point of the anchor onward, a narrow dragging trace is to be seen for several kilometers, which matches size-wise with the part connecting the anchor to the chain.
Photographs taken by the Finnish border guard show the concrete and steel layers around the pipeline have been crushed.
It is still not known if the damage was deliberate or accidental.
The trail and vessel tracking data suggest the Hong Kong-flagged Newnew Polar Bear could be behind the incident.
"Besides we could not visually confirm that both front anchors of the vessel were in their place, which helped in focusing the suspicions on this particular ship," Lohi said.
Finland's national broadcaster Yle published a photo of the vessel taken on October 22 which shows it is missing an anchor.
At the press conference, Lohi said that Newnew Polar Bear was contacted several times, but they were not willing to cooperate.
As the incident occurred in Finland's area of economic interest rather than on its territory, only limited steps can be taken.
"The police had no competence to take any coercive measures against the vessel, since it sailed in the exclusive economic zone of Finland, which is out of the police competence in this respect," Lohi said.
"We were constantly on alert to act, if the vessel had entered the Finnish territorial waters."
Open source shipping tracking data shows the Newnew Polar Bear was in the Gulf of Finland on October 8 around the time Balticconnector experienced a sudden drop in pressure.
Minister: Findings highlight need for international cooperation
In response to the NBI's announcement, Minister of Foreign Affairs Margus Tsahkna (Eesti 200) said this shows international cooperation is needed.
"The anchor that was found and the published images confirm that the damage to our undersea infrastructure was man-made," he said in a statement.
"The investigation is looking at all vessels who were in the area at the time the damage occurred, focusing on one specific ship. I hope we will receive the necessary support from China to make constructive contact with the crew and owners of the ship. Identifying all circumstances related to the incident requires a joint effort from several countries."
This article was updated to add a comment from Minister of Foreign Affairs Margus Tsahkna.
Editor: Helen Wright, Marko Tooming, Karl Kivil