A letter from lawyers for President Trump, seen in the Oval Office on Wednesday, asserts that his income from Russian sources in the past 10 years has been limited to real estate sales, a hosting stint in Moscow for the Miss Universe pageant and rounds of golf. (Jabin Botsford/The Washington Post)

The White House on Friday released a letter from two tax attorneys for President Trump claiming that his only income from Russian sources in the past 10 years came from fees for hosting the Miss Universe pageant in Moscow in 2013, his sale of a Palm Beach mansion to a Russian businessman in 2008 and his company’s routine sales of condo units and rounds of golf to Russians.

The attorneys said that their analysis came from a review of Trump’s tax returns for the past 10 years. However, they did not release the returns or provide any documents to support their claims.

The letter, from lawyers Sheri A. Dillon and William F. Nelson, also asserted that Trump holds no debt from Russian lenders and holds no equity in Russian entities. They explained that because of the way that Trump operates his businesses, his corporate income and debt would be disclosed on his personal tax returns.

[Trump lawyers’ letter on the president’s taxes]

Trump has come under increasing scrutiny over his possible ties to Russia — which he has denied — and is now facing a firestorm over his decision to fire James B. Comey as FBI director. Comey had been leading an investigation of Russian influence on the 2016 election and exploring whether any Trump associates had been involved.

(Jason Aldag,Sarah Parnass/The Washington Post)

Daniel Shaviro, a tax-law expert at New York University, said that without additional information on Trump’s tax returns and income, the letter from the lawyers is “meaningless garbage.”

“There are too many ways that it could be misleading and incomplete, Shaviro said. “For example, suppose that Russian people controlled U.S. entities that were intermediaries. Or suppose that things were run through Russian allies, including former Soviet countries.”

He said the fact that the White House would release such a letter with no verification “makes me more suspicious, not less, of the president’s financial ties.”

[Trump said he was thinking of Russia controversy when he decided to fire Comey]

According to the letter, income from the Miss Universe pageant made up a “substantial portion” of the $12.2 million in foreign income that Trump reported in 2013. His lawyers also noted that he sold a home in Palm Beach to a Russian buyer in 2008 for $95 million — $54 million more than he had purchased the home for in 2005. They also said Trump had earned an “immaterial” amount in sales of real estate and other products to Russians, transactions that would not be reflected on his tax returns.

With those exceptions, they said, Trump’s returns do not reflect “any income of any type from Russian sources.”

Critics have raised questions about whether Russians have funneled money through Trump or his projects into the United States. The letter is less clear about whether Trump has borrowed or received any money from Russian sources. It says his tax returns do not reflect any “debt” to Russian lenders, but, depending on the type of debt, it would not necessarily be listed on a tax return.

[The Daily 202: Trump’s warning to Comey deepens doubts about his respect for the rule of law]

The letter also says that no Russian sources have “any equity investments” in organizations that Trump controls. That means that Russian sources were not legal investment partners on any project that the Trump Organization pursued. But borrowing money from Russian sources could mean a number of things and would not necessarily represent an “equity investment.”

In 2008, Trump’s son Donald Trump Jr. said at a real estate conference that Trump businesses “see a lot of money pouring in from Russia.”

“Russians make up a pretty disproportionate cross-section of a lot of our assets,” Donald Trump Jr. said at the time.

If the tax lawyers reviewed the president’s past 10 tax returns, it is likely that they did not review the years to which Trump’s son, a top company executive, was referring.

Steven M. Rosenthal, a senior fellow at the Tax Policy Center, who practiced tax law in Washington for 25 years, described the letter as “very narrowly crafted by clever lawyers.”

He noted that the letter did not address the possibility of indirect transactions. Rosenthal said it would be unusual for Trump to borrow money directly from a Russian entity or for him to invest directly in a Russian entity. Those sorts of transactions are traditionally done through third parties in other countries, such as Cyprus or the Cayman Islands, Rosenthal said.

[Inside Trump’s financial ties to Russia and his unusual flattery of Vladimir Putin]

“In cross-border investments, a Russian typically would advance funds to some foreign corporation like a Cyprus corporation, which would then loan to Trump or Trump’s business,” Rosenthal said, speaking hypothetically. “Likewise, when American businesses invest in Russia, they don’t invest directly in Russian entities, they invest in a Cyprus corporation or a Cayman corporation.”

The letter from the lawyers, he said, “is silent on indirect investment, which is the conventional way to make these sorts of investments.”

On Tuesday, Sen. Lindsey O. Graham (R-S.C.) said that he thought Congress should investigate Trump’s business ties for possible Russian connections, including perhaps requesting Trump’s tax returns. Breaking with past precedent for U.S. presidents, Trump has refused to release his returns publicly.

Trump and his aides have been promising for several days that they would send a certified letter from Trump’s attorneys to Graham showing that the president has no business ties with Russia. “Certified” refers to the class of mail used to send the document, but does not offer any outside assurance that the contents of the document are accurate.

“I just sent a letter to Lindsey O. Graham from one of the most prestigious law firms in the country — tremendous, highly rated law firm — that I have nothing to do with Russia,” Trump told NBC’s Lester Holt on Thursday.

On Tuesday, White House press secretary Sean Spicer told reporters that Trump had “charged a leading law firm” to send a letter to Graham showing that “he has no connections to Russia.”

The letter released Friday is dated March 8 and addressed to Trump. A White House spokeswoman did not immediately respond to a question about why the letter was written in early March and why it was not released publicly for more than two months.

Tom Hamburger contributed to this report.