Germany is investigating Poland's involvement in the sabotage of the Nord Stream gas pipeline carried out in September 2022, which destroyed one of the largest infrastructures in the world and potentially Europe's largest source of energy.

An exclusive report by The Wall Street Journal on Saturday revealed that Germany's Federal Criminal Police Office is looking into evidence that might indicate that Poland was the operation's base to organize the attack on the pipelines.

Germany's Criminal Police Office found that a Warsaw-based firm Feeria Lwowa - which has been dormant for years and is owned by a Ukrainian citizen - rented a luxury yacht called Andromeda from a German company, located near the pipelines, that was used in the terrorist operation.

Read more: Polish PM hopes Nord Stream never becomes operational again

Earlier this week, a report by The Washington Post said the CIA knew through a European spy agency three months before the sabotage attack that members of a Ukrainian special operations team intended on blowing up the NordStream pipeline. 

The yacht according to the investigators was loaded with explosives and made a deviation from its original route into Polish waters come from the Danish island of Christianso.

The Federal Prosecutor's Office of Germany confirmed last March that searches had been carried out on a ship that was carrying explosives to blow up the Nord Stream gas pipelines.

According to the WSJ report, the investigators who searched the boat in January found traces of HMX - also referred to as octogen, a colorless substance well-suited for demolishing underwater infrastructure.

The yacht crew planted the explosives before heading toward Poland, the report added, noting that navigation hardware, satellite, and mobile phones, as well as Gmail accounts used by the perpetrators, were discovered on the ship. But the most notable finding was DNA samples that investigators are trying to match with suspected personnel.

Attempting to distance Warsaw from the operation, a senior Polish national security official said, “I can assure you that no Polish institution is involved in this story, and this is not a state case," but “I cannot exclude that some Polish company or whatever is involved in this case.”

Immediately after the explosion, former Polish minister and member of the European Parliament Radoslaw Sikorski thanked on his Twitter account the United States, referring to Washington's possible role in cutting off the energy infrastructure.

He also tweeted in Polish that if Russia wants to continue supplying gas to Europe, it must "talk to the countries controlling the Brotherhood and Yamal gas pipelines, Ukraine and Poland." 

However, Sikorski later deleted both tweets.

Poland, which claims that it has been conducting its own investigation, has been trying for months to figure out what Berlin is investigating, the report revealed.

In March, investigative journalist Seymour Hersh said President Joe Biden was responsible for ordering the Nord Stream pipeline explosion in September last year by using C-4 charges planted by US Navy divers.

He revealed that it was Norway that pointed out to the US the location of where the underwater pipeline was closest to the surface to facilitate the US operation.