The German federal prosecutor's office searched a boat in January that was suspected of carrying explosives used in the Nord Stream 1 and 2 gas pipeline detonations in September, according to a statement from the prosecutors office.
"The Office of the Attorney General of Germany had a ship searched from January 18 to 20, 2023 in connection with a suspicious ship rental," the statement details.
"The evaluation of the seized traces and objects is ongoing. The identity of the perpetrators and their motives are the subject of ongoing investigations," it said.
Investigations are ongoing, and reliable statements cannot be issued yet, particularly as to whether a state controlled these plans, it added.
It comes after a media report cited new intelligence that a "pro-Ukrainian group" may have been behind the attack last year.
"There are no grounds for suspecting employees of the German company that leased the ship," the office said.
More details from German public broadcaster's report: The boat left the Baltic sea port of Rostock, Germany, on September 6, 2022, according to German public broadcaster ARD, citing its own investigation. The ARD reporting cited unnamed security sources from five countries.
ARD said the boat carried six people: one captain, two divers, two assistant divers and a doctor. The nationalities of those six are not known, according to ARD. The broadcaster said the group was using professionally falsified passports to rent the boat.
A truck delivered the group's gear to the harbor beforehand, it said.
ARD said the investigators, according to its research, were able to piece together the route of the boat after September 6: It went to Wieck, a German municipality east of Rostock, and could also be pinned on the Danish island of Christiansø, northeast of Bornholm.
The boat was according to ARD returned in a dirty state and the investigators, according to the broadcasters research, were able to find traces of explosives on the cabin table.
The German prosecutors office declined to give any more information when asked for any further details.
CNN also approached the port of Rostock and is awaiting a response, but it is a public holiday today.