In her final months as German chancellor in 2021, Ms Merkel told Handelsblatt that there had been no reason to believe Russia was limiting gas deliveries.

However, according to confidential documents seen by the newspaper, the economy ministry warned that Russia was filling gas storage facilities “very slowly” and that relying on the Kremlin for gas could have “dramatic consequences”.

The revelation comes as new documents published by Süddeutsche Zeitung, the newspaper, also showed that two consecutive Merkel governments intensively pushed for Nord Stream 2 to come online, claiming its deal with Gazprom, the energy company – which is majority state-owned – was a “private-sector project”.

This was despite repeated criticism of the project from the US and European allies, which said the pipeline would make Europe too reliant on Russian gas. Other European governments said the link was vital to secure energy supplies amid a surge in gas prices in 2021.

Germany told the Kremlin that a condition of the deal, which had been set to transport Russian gas 761 miles through the Baltic Sea, was that Russia would continue to use onshore gas pipelines through Ukraine.

But internal economy ministry documents warned after a meeting with Gerhard Schröder, the former German chancellor-turned-Gazprom lobbyist, that the state fossil fuels giant “could not be forced” to do so.

After Russia invaded Ukraine, Nord Stream 2 was officially cancelled. Both pipelines – Nord Stream 1 and 2 – were then destroyed by unknown attackers in September that year.