It was reported earlier that as part of his probe into possible collusion between Russian Federation and the Trump campaign, Mr Mueller asked Deutsche Bank to share data on accounts held by Mr Trump and his family.
Before Trump became president, the bank loaned the Trump Organization hundreds of millions of dollars for various real estate projects.
As The New York Times noted earlier this year, Deutsche Bank is basically the only major financial institution that continues to do "sizable" business with Trump in the wake of his series of high-profile bankruptcies.
The bank told Bloomberg in a statement that it always cooperated with investigating authorities. The attack followed the guilty plea of Trump's former national security adviser, Michael Flynn, who is now cooperating with federal investigators.
Trump plugs interview with lawyer saying president did nothing wrong
The House in 1998 approved two articles of impeachment against Clinton, one of which was for obstruction of justice. Comey testified that he "took it as a direction" to drop the probe into Flynn, but did not obey it.
Though Flynn already admitted that other top transition officials - including Jared Kushner, the president's son-in-law, and K.T. McFarland, who is now nominated to be the US ambassador to Singapore - were aware of his Russia-related dealings, Mueller is likely to want to talk to him about a wider range of topics, including whether Trump obstructed justice and tried to short circuit the probe.
Russian Federation has denied US intelligence agencies' conclusion that it meddled in the election and Trump has said there was no collusion with Moscow.
Holding Trump debt, particularly if some of it was or is soon due, could potentially give Russian banks some leverage over the US President, especially if they are state-owned, said a second US official familiar with Russian intelligence methods. "So we're very happy". So when he set out to relaunch his empire, he turned to Deutsche Bank for the financing he couldn't find elsewhere. Representative Maxine Waters of California and other Democrats have asked whether the bank's loans to Trump, made years before he ran for president, were in any way connected to Russian Federation. While some critics of the anti-Trump camp are calling the reports about the Trump finances subpoena "fake news", it isn't fake as much as it might be a half-truth.
Holding Trump debt, particularly if some of it was or is coming due, could potentially give Russian banks some leverage over Trump, especially if they are state-owned, said a second US official familiar with Russian intelligence methods. We've already seen that with the indictment of Paul Manafort and Rick Gates for money laundering and rarely-charged FARA violations, none of which had to do with the theory of Russian collusion that started the investigation.
But until Mueller opts to bring his investigation into the public eye, we're unlikely to know for sure whether he's made a decision to cast his net so broadly. Trump likely didn't commit obstruction in the legal sense in firing Comey, but he'd be clearly committing obstruction in the political sense if he fired Mueller now.