Two senior officials at Germany's economy ministry are being investigated over allegations of spying for Russia, newspaper Die Zeit reported on Wednesday.

According to the article, the Federal Office for the Protection of the Constitution (BfV), Germany's domestic intelligence service, is looking into the case of two civil servants "who are involved with energy supply in key positions" and might be Kremlin moles.

If confirmed, the case would represent a spectacular security breach at a highly sensitive time for Germany and for Europe. The economy ministry did not immediately respond to a request for comment.

The powerful ministry is under the leadership of Economy and Climate Minister Robert Habeck, who also serves as Chancellor Olaf Scholz's deputy. It is playing a key role in preparing Germany to cope with an energy crisis as Russian President Vladimir Putin cuts gas deliveries in response to Western sanctions over his invasion of Ukraine.

One of the most sensitive questions that faced German officials was whether to go ahead with Nord Stream 2, a planned gas pipeline from Russia.

For years, Germany's governments have defended the Nord Stream 2 project as "merely commercial." The pipeline project was halted after the invasion of Ukraine but Die Zeit reported that security concerns were raised over the content of internal documents relating to Nord Stream 2.

Earlier this year, Habeck's advisers turned to the BfV for assistance over "inconsistencies in the internal papers on Nord Stream 2 and the filling level of the gas storage facilities, as well as in the report on Germany's security of supply," Die Zeit reported.

The pipeline project was halted after the invasion of Ukraine but Die Zeit reported that security concerns were raised over the content of internal documents relating to Nord Stream 2

Germany has been debating for months efforts to move away from Russian gas and replace it with deliveries from elsewhere, including Qatar, Norway and Canada. Habeck and other Cabinet members frequently stressed how determined they are to move Germany away from dependency on Putin's gas.

But at the economy ministry, "many documents ... were full of understanding for the Russian point of view, and it was striking that the argumentation often did not fit the official line of the German government," Wednesday's newspaper report said.

Upon investigating the suspects, their backgrounds and travel histories, the BfV found "biographical anomalies, in one case a study visit to Russia" and internally there was talk of an "emotional closeness to Russia," it continued. Such closeness alone could not be counted as damning evidence given many among Berlin's political elite have long sustained cordial ties to the Kremlin, the report said.

If the suspicions were to be vindicated, however, the incident would mark a major embarrassment for Germany and its current government as well as a public relations triumph for Putin.