Swedish police said on Thursday that they had boarded the Yi Peng 3 vessel, at the invitation of the Chinese authorities.
The Yi Peng 3 vessel is at the centre of an investigation into Baltic Sea cable breaches.
The Chinese bulk carrier is wanted in Sweden for questioning over a breach of two undersea fibre-optic cables in November.
While the Swedish police participated as observers, representatives from Denmark, Finland and Germany were also on board.
The Chinese carrier has been stationary in waters nearby for a month while diplomats in Stockholm and Beijing discussed the matter.
Investigators quickly zeroed in on the ship, which left the Russian port of Ust-Luga on November 15.
A Reuters analysis of Marine Traffic data showed that the vessel’s coordinates corresponded to the time and place of the breaches.
Swedish police said on Thursday they participated on board the Yi Peng 3 as observers only, while Chinese authorities conducted investigations.
“In parallel, the preliminary investigation into sabotage in connection with two cable breaks in the Baltic Sea is continuing,” the police said in a statement.
The actions taken on board the ship on Thursday were not part of the Swedish-led preliminary investigation, the police added.
Danish authorities are facilitating the visit to the bulk carrier, which is anchored in the Kattegat strait between Denmark and Sweden, police said.
The Baltic Sea cables, one linking Finland and Germany and the other connecting Sweden with Lithuania, were damaged on November 17-18.
This prompted German Defence Minister Boris Pistorius to say that he assumed it was caused by sabotage.
The breaches happened in Sweden’s exclusive economic zone and Swedish prosecutors are leading the investigation on suspicion of possible sabotage.
Western intelligence officials from several countries have said they are confident the Chinese ship caused the cuts to both cables.
But they have expressed different views on whether these were accidents or could have been deliberate.
Swedish Prime Minister Ulf Kristersson has urged the ship to return to Sweden to aid the investigation.
The was no immediate response from the Chinese foreign ministry outside of business hours on Thursday.
(With inputs from Reuters)
