The Ukrainian government was not involved in the sabotage last year of the Nord Stream gas pipelines in the Baltic Sea, the country's defence minister said Wednesday.

"This is not our activity," Defence Minister Oleksiy Reznikov told reporters in Stockholm ahead of a meeting with EU defence ministers, in response to a report in The New York Times on Tuesday that US officials had seen new intelligence indicating a "pro-Ukrainian group" was responsible for the sabotage.

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

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

It also stoked the surge in energy prices weighing on key Ukrainian allies, particularly Germany.

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

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

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

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

According to separate German media reports, German investigators believe the unidentified group was made up of five men and one woman using professionally falsified passports, and who rented a boat that set sail from the northern German port of Rostock.

German investigators found traces of explosives on the table in the boat's cabin, according to the report by German broadcasters ARD and SWR and the weekly magazine Die Zeit.