Ukraine's Zelensky has repeatedly denied his country was behind the sabotage. (File)
A Ukrainian special forces commander played a key role in sabotaging the Nord Stream gas pipelines in September last year, reports said Saturday.
Mystery has surrounded who was behind the blasts that damaged the pipelines, cutting off a major route for Russian gas exports to Europe and fuelling already high tensions over Moscow's invasion of Ukraine.
Different theories have emerged pointing the finger at Ukraine, Russia or the United States. All have denied involvement.
A joint investigation by The Washington Post newspaper and German outlet Der Spiegel singles out Roman Chervinsky, a 48-year-old who served in Ukraine's Special Operations Forces.
He was the "coordinator", the reports said, citing officials in Ukraine and elsewhere in Europe, as well as other people with knowledge of the operation, who spoke anonymously.
He oversaw logistics and support for a six-person team, which rented a sailing boat using false identities and diving equipment to place explosive charges on the pipelines, said the Post.
The blasts ruptured three of the four pipelines that make up Nord Stream 1 and Nord Stream 2, spewing gas into the Baltic Sea.
Chervinsky did not plan the operation or act alone, and took orders from more senior Ukrainian officials, the Post reported.
He denied any role in the sabotage through his lawyer.
"All speculations about my involvement in the attack on Nord Stream are being spread by Russian propaganda without any basis," he said in a statement to the Post and Der Spiegel.
Ukraine's President Volodymyr Zelensky has repeatedly denied his country was behind the sabotage.
"I would never do that," he told Germany's Bild newspaper in June, adding that he would "like to see proof".
But the Nord Stream operation was designed to keep Zelensky in the dark, the Post reported.
The two media outlets said the Ukrainian government did not respond to requests for comment on their investigation.
Chervinsky is currently on trial in Kyiv, accused of having abused his power during an attempt to persuade a Russian pilot to defect.
He says his prosecution is political retribution for having criticised Zelensky, according to the reports.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)