A media report that a “pro-Ukrainian” group may have been behind last year’s attack on the Nord Stream gas pipeline is “hard to believe," the Kremlin said Thursday.

“As for some pro-Ukrainian ‘doctor evil’ who organized this, it's hard to believe,” Russian spokesperson Dmitry Peskov told reporters on a daily call.

“It was too difficult a task that only a well-trained special state service could handle. There aren't many of them in our world,” he said.

“We continue to demand a prompt and transparent investigation,” Peskov said.

Moscow will demand to be admitted to the investigation, he added, calling the theory that Russia was involved in the explosions “completely unfounded and unsubstantiated.”

“Now, no matter what happens, Russia is the first to be blamed. Of course, this hoax does not stand up to scrutiny. It is completely unfounded and unsubstantiated, absurd in nature,” he said.

What Ukraine is saying: Ukraine has denied any involvement in the sabotage of the Nord Stream pipelines following a media report citing new intelligence that a “pro-Ukrainian group” may have been behind the attack.

Mystery has surrounded who might be responsible for the brazen sabotage last September which damaged two pipes transporting Russian gas into the European Union and targeted a crucial source of revenue for Moscow.

Both pipelines were closed at the time of the attack, which came months after Russia’s invasion of Ukraine.