US intelligence sees 'pro-Ukraine group' behind Nord Stream sabotage: Report

US officials have seen new intelligence that indicates a "pro-Ukrainian group" was responsible for the sabotage last year of the Nord Stream gas pipelines, the New York Times reported Tuesday, claims dismissed by a senior Ukrainian official.

In a cautious report that did not identify the source of the intelligence or the group involved, the Times said the US officials had no evidence implicating Ukrainian President Volodymyr Zelensky in the pipeline bombing.

But the attack benefitted Ukraine by severely damaging Russia's ability to reap millions by selling natural gas to Western Europe.

At the same time, it added to the pressure of high energy prices on key Ukrainian allies, particularly Germany.

The intelligence suggested the perpetrators behind the sabotage were "opponents of President Vladimir V. Putin of Russia", the Times report said.

"Ukraine has nothing to do with the Baltic Sea mishap and has no information about 'pro-Ukraine sabotage groups'," presidential adviser Mykhailo Podolyak tweeted on Tuesday.

US officials had no indication of who exactly took part or who organized and paid for the operation, which would have required skilled divers and explosives experts.

They believed those involved were probably Ukrainian or Russian nationals, and that none were from the United States or Britain.

Rented yacht

German investigators believed the unidentified group was made up of five men and one woman using professionally falsified passports, according to separate German media reports.

German officials had identified the boat suspected to have been used in the attack, according to the broadcasters ARD, SWR and weekly magazine Zeit.

The yacht in question was said to have been rented out by a company based in Poland, belonging to two Ukrainians, per the German report, which referred only to sources in multiple countries.

The commando group is said to have set sail from the north German port of Rostock on September 6, 2022 and was localised the following day on the Danish island of Christianso in the Baltic.

The yacht was subsequently returned to the owner uncleaned, with investigators able to find traces of explosives on the table in the cabin, according to the detailed report.

The pipelines were ruptured by subsea explosives on September 26, seven months after Russian forces invaded Ukraine.

US officials have "no firm conclusions" about the intelligence, "leaving open the possibility that the operation might have been conducted off the books by a proxy force with connections to the Ukrainian government or its security services", the Times said.

The lack of a firm suspect meant international intelligence officials had not ruled out the possibility of a "false flag" operation to link the attack to Ukraine, per the German media.

'Wrong to speculate'

Authorities in Germany, Sweden and Denmark have opened probes into the incident.

A spokeswoman for the German government said it had "taken note" of the New York Times' report, referring back to the ongoing investigation.

"There is an ongoing preliminary investigation in Sweden, so I do not intend to comment on those reports," Swedish Prime Minister Ulf Kristersson told reporters late Tuesday.

Speaking at the same press conference, NATO Secretary General Jens Stoltenberg echoed the remarks, saying it would be "wrong to speculate" before the investigations were completed.

In February, veteran US investigative journalist Seymour Hersh reported that the United States was behind the operation to bomb the Nord Stream pipelines and that Norway assisted.

The White House blasted Hersh's report, which cited an unnamed source, as "complete fiction."