(CNN) — Dutch public radio said Tuesday that the country’s military intelligence last year warned the CIA about a Ukrainian plan to blow up the “Nord Stream” natural gas pipeline.

The report is based on a joint investigation conducted by the Dutch and German, the radio said.

As CNN reported last week, the U.S. received intelligence from a European ally last year that the Ukrainian military was planning an attack on Nord Stream pipelines, based on information from 3 U.S. officials.

US officials and Western allies condemned the attack on the pipelines last September, calling it “sabotage of critical infrastructure”, and the incident is being investigated by other European countries.

The Wall Street Journal reported Tuesday, citing well-informed officials, that the CIA warned Ukraine last year against attacking Nord Stream after receiving information about the alleged Ukrainian project.

Officials told the newspaper that US intelligence had received the information from Dutch military intelligence.

The Dutch Public Broadcasting Corporation said in its report that Dutch military intelligence was able to collect detailed information about the Ukrainian plan to blow up the pipelines at an early stage.

The CIA and the Dutch embassy in the U.S. declined to comment when CNN reached out for comment on Tuesday. CNN asked the Ukrainian government for a response, but it did not respond.

The Dutch broadcaster’s report comes less than a year after the discovery of leaks caused by underwater explosions in the Nord Stream 1 and 2 pipelines that carry gas from Russia to the European Union under the Baltic Sea.

The pipeline was controversial before the start of the war in Ukraine, raising concerns about Europe’s dependence on Russian gas.

Neither pipeline was actively transporting gas to Europe at the time of the spill, although they still held gas under pressure.

Ukraine denied any responsibility for the leaks at the time, with Mykhailo Podoliak, a senior adviser to Ukrainian President Volodymyr Zelensky, calling the idea an “entertaining conspiracy theory” via Twitter.