"We are following-up on specific allegations regarding the President's actions based on corroborating documents obtained by the Committee, and we will continue our efforts to conduct credible, robust, and independent oversight," Cummings told the Washington Post.
The request relates to former Trump lawyer Michael Cohen's testimony before the committee in late February. Cohen provided copies of financial statements for 2011, 2012 and 2013, which he said Trump had sent to Deutsche Bank in pursuit of a loan to buy the NFL's Buffalo Bills in 2014. Cohen said the same sort of statement had been sent to Trump's insurers, in an attempt to lower Trump's premiums by reassuring lenders about Trump's ability to pay them.
Two of those statements, from 2011 and 2012, are signed by Mazars. The 2013 statement is shorter, and unsigned.
Both Mazars and the Trump Organisation did not immediately respond to requests for comment.
The statements of financial condition were a longtime tool used by Trump to summarise his assets, debts, and net worth for potential lenders and business partners.
During his testimony, Cohen - Trump's longtime attorney, now headed to prison for lying to Congress in a previous hearing - said Trump sometimes exaggerated the numbers to make himself appear wealthier. He said, for instance, that Trump would inflate the values of his commercial buildings by taking the rent their tenants paid, and multiplying it by a number Trump himself chose. But Cohen also alleged that Trump would deflate his assets to pay less taxes.
In that hearing, Congresswoman Alexandria Ocasio-Cortez asked Cohen if the committee needed "to review his financial statements and his tax returns in order to compare them?"
Cohen said simply, "Yes."
Analysis: Democrats confront their post-Mueller dilemma
Aaron Blake
For the better part of the past two years, Democratic leaders in Washington have successfully quelled the impeachment fervour that has existed within their ranks.
The worry has clearly been about overreach: that Democrats would look overzealous in politically prosecuting US President Donald Trump for alleged misdeeds, and it would backfire - like it did on Republicans in 1998 - by making Trump sympathetic.
And yet, with impeachment looking all but off the table following the release of the Mueller report's chief conclusions, they're finding themselves with a similarly fraught balancing act.
Even though Special Counsel Robert Mueller declined to accuse Trump of obstruction of justice or his 2016 campaign of collusion with the Russian government, Democratic leaders have largely stuck to their previous assertions that both appear to have taken place and should be probed further.
"Undoubtedly there is collusion," House Intelligence Committee Chairman Adam Schiff said this week. Schiff had said for weeks that "clear evidence" of collusion exists, and this was a double down. He also assured he would probe whether Trump is compromised by the Russians, arguing Mueller doesn't appear to have looked at that question.
Representative Jerrold Nadler the head of the House Judiciary Committee in charge of obstruction-related questions, appears similarly assured. He said earlier this month that it was "very clear" that Trump had obstructed justice, even as he acknowledged the burden of proof needed to be met.
And after Attorney-General William Barr reported this week that Mueller had neither accused Trump of obstruction nor exonerated him, Nadler suggested Barr's letter might be politically slanted.
It's entirely possible that's true. As I've argued, there are real questions about Barr's role and the appropriateness of him personally exonerating Trump on obstruction, when Mueller hadn't.
Unless and until we see the actual report and its obstruction-related findings, we don't know how problematic Trump's conduct might be. It's also true that Democrats have earned the power to probe these questions themselves, by virtue of winning the House in the 2018 election.
But as with impeachment, just because they can move forward aggressively doesn't mean it will pay off. And it's one thing to say you want to reach your own conclusions; it's another to look like you've drawn those conclusions before the investigation is complete.
Democrats have boxed themselves in, to some degree, by arguing that these crimes were committed and then having Mueller - after an intensive nearly two-year-long investigation - concluding they can't be proved. Whatever else Mueller has found, the fact will remain that he decided these weren't crimes.
It's possible Democrats could uncover something more incriminating, and some have wagered that Schiff's assuredness suggests he already has. That's rank speculation, though, and it's just as possible he and other top Democrats are simply too invested in these ideas to back off them now. Abandoning the cause now would mean tacitly admitting they were wrong and would surely result in a disillusioned base.
But at this point, to override the conclusions of a special counsel in Americans' minds, Democrats would need to produce some real smoking guns. They would need something extremely compelling, rather than the circumstantial cases Mueller has apparently wound up with. There are many compelling dots that can be connected, but convincing people they should be connected is a tall order.
And if they wind up with much of the same evidence as Mueller and simply offer harsher conclusions, it risks looking politically motivated. It risks looking like they have disregarded the work of the man they had invested so much time in defending from Trump's attacks because they desired particular outcomes. And Republicans will credibly be able to make the case that they prejudged those outcomes, based upon the quotes above.
In a lot of ways, it could look like the worst-case scenario would have looked with an impeachment.
