The European intelligence reporting was shared on the chat platform Discord, allegedly by Air National Guard member Jack Teixeira. The Washington Post obtained a copy from one of Teixeira’s online friends.

The intelligence report was based on information obtained from an individual in Ukraine. The source’s information could not immediately be corroborated, but the CIA shared the report with Germany and other European countries last June, according to multiple officials familiar with the matter, who spoke on the condition of anonymity to discuss sensitive intelligence operations and diplomatic discussions.

The highly specific details, which include numbers of operatives and methods of attack, show that for nearly a year Western allies had a basis to suspect Kyiv in the sabotage. That assessment has only strengthened in recent months as German law enforcement investigators uncovered evidence about the bombing that bears striking similarities to what the European service said Ukraine was planning.