Danish police have searched for a yacht on a tiny Baltic Sea island near the Nord Stream pipeline blast sites, the local administrator said on Thursday.
German authorities confirmed on Wednesday they had raided a ship in January that may have been used to transport explosives used to blow up the pipelines.
"The police was searching for a specific boat that had moored here in September," Soren Thiim Andersen, the highest authority on the island of Christiansö, told Reuters.
The Sept. 26 explosions on the Nord Stream pipelines, constructed to supply Russian natural gas to Europe, have become a flashpoint between the West and Russia after last year's Russian invasion of Ukraine.
Authorities in Sweden, Germany and Denmark, who are currently investigating the blasts, say the explosions were deliberate but have not said who might be responsible.
However, this week media reports in the United States and Germany suggested a pro-Ukrainian group could be responsible.
Germany's ARD broadcaster and Zeit newspaper reported that German authorities were able to identify a boat used for the sabotage operation.
The operation to place explosives on the seabed was carried out by six people, who sailed from Rostock on Sept. 6 and was later located on the Danish island of Christiansö, according to the reports.
Danish police in January searched for information about boats that had docked on Christiansö on Sept. 16-18, interviewing local residents, collecting footage from the harbour, and collected information from the harbour ticket machine, Andersen said.
Danish police declined to comment.
Christiansö is part of a small archipelago about 18 km northeast of the Baltic Sea island of Bornholm. The archipelago with just 98 inhabitants is a former naval fortress but remains under administration of the Danish defense ministry.
(Reuters - Additional reporting by Johannes Birkebaek; Editing by Jacob Gronholt-Pedersen)