Republican presidential candidate Donald Trump said he raised $6 million for veterans groups at a January fundraiser. The Washington Post's accounting, based on interviews with charities, only found $3.1 million in donations to veterans groups. In addition, almost four months after promising $1 million of his own money to veterans' causes, Trump moved to fulfill that pledge. (McKenna Ewen/The Washington Post)

UPDATE: On Tuesday afternoon, Trump told The Washington Post that he had made good on a promise to give $1 million to veterans groups -- but he had only done it on Monday night, under increasing media scrutiny. This post has been updated to reflect new information from that interview.

Since late Monday, Donald Trump has been using social media to denounce reporting about a fundraiser he held in Iowa on Jan. 28, to benefit veterans' groups.

"Bad publicity from the dishonest and disgusting media," Trump said on Twitter last night. "Absolutely disgraceful" Trump said in a video posted on Instagram today.

Some of that reporting has been done by The Washington Post, including a story posted Friday, in which Trump's campaign manager said that the actual total raised was less than the $6 million Trump claimed at the time.

As of now, here's what we know -- and what we don't -- about the money Trump raised.

How much money did Trump actually bring in?

We don't know for certain.

Trump said Tuesday that he'd raised about $5.5 million. That differed from the figure given last week by Trump campaign manager Corey Lewandowski, who told The Post Trump had raised about $4.5 million. A better accounting will be possible in the coming days: Trump's campaign has promised that the last money from the fundraiser will be given away to veterans' groups by Memorial Day. When those outgoing donations are counted, we may know for sure what was raised.

Why did the total fall short of the $6 million that Trump claimed?

It's still not clear.

Last week, Lewandowski said the shortfall was the fault of Trump's own wealthy acquaintances. He said some donors had pledged to give, but then backed out. He did not say who.

But, on Tuesday, Trump said that was wrong. In fact, he said, all the big donors had followed through on their pledges -- though some came in late. Trump himself could be counted as one of those late givers, since his $1 million pledge was not fulfilled until this week.

Did Trump give any money out of his own pocket?

Trump says he did.

On Monday night, Trump called the home of James Kallstrom, a retired FBI official who is chairman of the Marine Corps-Law Enforcement Foundation. That foundation, which helps the families of fallen Marines and federal law-enforcement officers, has received donations in the past from Trump's personal foundation. Trump said he would be making a $1 million donation, giving his entire gift to a single charity. [Last week, Trump's campaign manager had said the money had already been spent. That turned out not to be true.]

We are still waiting for confirmation from the Marine Corps-Law Enforcement Foundation that Trump's money has been transferred, and that the money indeed came from Trump's personal fortune.

“The foundation is thrilled, because the [money] is going to help a lot of people. Especially the children," said Sue Kallstrom, the chairman's wife. The gift was made after 8 p.m. on Monday night, after The Post had spent the day making a public search on Twitter -- Trump's preferred social-media platform -- for  any sign of a $1 million personal gift.

How much money has actually been given away to veterans' groups so far?

At least $3.1 million, by The Post's most recent accounting. That number would rise to $4.1 million, with the addition of Trump's personal gift.

The Post's accounting of the other gifts has relied on reports from the veterans' groups themselves, and from information provided in early March by the Trump campaign. When The Post showed this accounting to Lewandowski last week, he said, "You’ve got a pretty good handle on a lot of the money that’s been pretty distributed."

Some of this $3.1 million was given directly to veterans' charities by other donors who were inspired by Trump. In some cases, big donors sent their money to the Donald J. Trump Foundation, which passed the money on. In all, 28 charities received money.

The Post has asked the Trump campaign repeatedly for the amount of money still remaining to be given away. That number has not been provided.

While campaigning in Nashua, N.H., Republican presidential candidate Donald Trump says he did the "right thing" when he did not join Thursday night's debate. Instead of attending the seventh Republican debate, Trump held an event across town for U.S. military veterans. (Reuters)

Are these charities chosen by Trump legitimate?

By all appearances, yes. The recipients included large, well-known organizations such as the Disabled American Veterans charity and the Marine Corps-Law Enforcement Foundation, as well as small charities that do things such as train service dogs to help disabled veterans. One group identified as a recipient of the money -- Projects for Patriots, an Iowa-based group that refits houses for disabled vets -- said it has not received its money yet, because it still needs to be officially certified as a charity by the Internal Revenue Service.

What will happen to the rest of the money?

It will be given away by Monday -- Memorial Day -- Lewandowski told CBS.

Lewandowski earlier told The Post that the Trump campaign identified "probably two dozen or more" charities that would get the money, in amounts ranging from $20,000 to $100,000. On Tuesday, a veterans' charity in Boston reported receiving a phone call from the Trump campaign, asking for its tax ID number. The understanding was that some kind of gift would follow.