Special counsel Robert Mueller's "Russiagate" probe cost U.S. taxpayers $3.2 million in the first six months, mostly on salaries and benefits.
In a statement Tuesday, attorney Jay Sekulow says such reporting is "false" and says "no subpoena has been issued or received".
Deutsche Bank, which has loaned the Trump organisation millions of dollars for real estate ventures, said it would not comment on any of its clients.
Trump has done billions of dollars' worth of business with Deutsche Bank in the past 20 years; he has previously said that he would consider Mueller looking into his finances beyond any connection to the Russian Federation investigation "a violation".
Special Counsel Robert Mueller departs after briefing the U.S. House Intelligence Committee on his investigation of potential collusion between Russian Federation and the Trump campaign on Capitol Hill in Washington, U.S., June 20, 2017.
Special counsel Robert Mueller's office spent $3.2 million during the first few months of his investigation into Russian election interference and possible coordination with associates of President Donald Trump. Sources familiar with Trump's borrowing from the bank told The Financial Times the total he owed is more like $300 million.
There was no immediate response to the Deutsche Bank subpoena from Trump's lawyers.
In June Deutsche Bank cited privacy laws when it rejected a request by House Democrats to provide details of Trump's finances.
In 2012, his Trump International Hotel Hotel and Tower in Chicago was loaned up to $640m, according to a property filing. The one exception was Deutsche Bank, to which Trump owed $364 million as of the end of a year ago. In a recent tweet, Trump admitted that he knew then-national security adviser Michael Flynn lied to the FBI about his conversations with Russian ambassador Sergey Kislyak when he fired him, which means Trump knew Flynn had committed a crime when he asked then-FBI Director James Comey to lay off investigating Flynn. Papadopoulos pleaded guilty. Manafort and Gates pleaded not guilty.
The heat on the investigation of President Trump's finances has just been cranked up even further.