The Swedish Prosecution Authority and the country's foreign ministry refrained from commenting for purposes of confidentiality on the American investigative journalist's findings that US navy divers blew up Russia's Nord Stream pipeline.  

The press department of the foreign ministry stated that Sweden's relevant authorities were launching a criminal investigation and refused to elaborate. 

The prosecutor's press department also stated that the investigation into the Nord Stream sabotage is ongoing and that prosecutors could not comment owing to the case's confidentially.

Read more: US planted explosives that destroyed Nord Stream, claims Seymour Hersh

The explosions occurred on September 26 at three of the four strings of Nord Stream 1 and 2 underwater pipelines, which are designed to transport a total of 110 billion cubic meters of Russian gas to Europe each year.

Separate investigations were launched by Germany, Denmark, and Sweden into the suspected sabotage, with German media reporting trust issues among the three EU nations. The Russian prosecutor's office announced an investigation into possible international terrorism however Denmark and Sweden have barred Russia from investigating the attack.

Read more: Sweden, Denmark, and Germany to investigate Nord Stream issue separately

Acclaimed investigative journalist and Pulitzer prize winner Seymour Hersh reported that the United States was behind the explosions that destroyed Nord Stream.

Flightradar24 data showed in late September that US military helicopters habitually and on numerous occasions circled for hours over the site of the Nord Stream pipeline incident near Bornholm Island.

A US Navy Sikorsky MH-60R Seahawk helicopter spent hours loitering over the location of the damaged natural gas pipelines in the Baltic Sea near Bornholm for several days in a row, September 1, 2, and 3, in particular.

According to the article, the United States decided to sabotage the pipelines after a lengthy debate that lasted more than nine months inside the US national security community.

Hersh explains that the explosives were planted during a NATO exercise in the Baltic Sea last summer, in coordination with Norway who was instrumental in helping the US plan the attack and conceal it from the Swedish and Danish navies.

Read next: Polish EU Parliament member on Nord Stream explosion: "Thank you, USA"