The now-infamous Donald Trump Jr. meeting with a Russian lawyer during the presidential campaign had a previously undisclosed attendee. And that person is allegedly — I kid you not — a former Russian spook.

This latest news comes courtesy of a report published by NBC News on Friday morning. The man in question, according to NBC, is a “Russian-American lobbyist” and “a former Soviet counter intelligence officer who is suspected by some U.S. officials of having ongoing ties to Russian intelligence.”

NBC chose not to publish his name, but the Associated Press has identified him as Rinat Akhmetshin — a longtime Washington lobbyist who was accused in court filings of being a former Soviet military intelligence officer who "developed a special expertise in running negative public-relations campaigns” (a charge he denies).

Trump Jr. somehow failed to disclose Akhmetshin’s presence at the meeting, making this the fifth time he chose to either lie about the meeting or omit some vital piece of information about it. To make matters worse, his own lawyer, Alan Futerfas, partially confirmed the story in a statement to NBC — admitting that there was at least one previously undisclosed attendee, possibly even two, at the fateful meeting.

“He is a US citizen,” Futerfas told NBC, referring to the unnamed attendee presumed to be Akhmetshin. “He told me specifically he was not working for the Russian government, and in fact laughed when I asked him that question.”

Which is exactly what a spy would do if you asked them if they were a spy. “This is how it is done,” Glenn Carle, a CIA operative who spent 23 years at the agency, told me after reading NBC’s scoop.

Now, it’s too early to say with any certainty that Akhmetshin was actually a Russian spy. His ties to Russian intelligence are still murky at this point — he is a dual US-Russian citizen who has lived in the US since 1994 and worked in Washington for decades on all sorts of lobbying campaigns, including ones related to the Magnitsky Act, US sanctions punishing Russia for its human rights record.

But NBC’s report does prove, beyond a shadow of a doubt, that there’s more to this meeting than what we know right now. The Trumps are still lying to us.

It is impossible to believe the Trump account of the meeting anymore

My colleague Dara Lind has put together a comprehensive timeline of Donald Trump Jr.’s shifting stories on the Russia meeting. It’s worth reading in full, but here’s a shortened version:

First, Trump Jr. denied any meeting with Russians.

When the New York Times reported last Saturday that he had met with Russian attorney Natalia Veselnitskaya, he said it was “a short introductory meeting” about “a program about the adoption of Russian children” — which is code for lifting Magnitsky sanctions.

When the Times reported in a Sunday follow-up that Trump Jr. went to the meeting to get dirt on Clinton, he admitted this was right — that Veselnitskaya was “an individual who I was told might have information helpful to the campaign,” but didn’t mention any potential Russian government connections.

On Tuesday, to preempt yet another Times scoop, Trump Jr. published his emails with British publicist Rob Goldstone about the Veselnitskaya meeting — in which Goldstone states that the meeting was “part of Russia and its government’s support for Mr. Trump” and Trump Jr. replies that “if it’s what you say I love it.”

Now, on Friday, Trump’s camp has admitted there was at least one more person at the meeting that we didn’t know about — and it seems plausible that this person, Akhmetshin, has at least some kind of connection to Russian intelligence.

What this demonstrates, beyond a shadow of a doubt, is that the Trump camp cannot be trusted, at any point in time, to be telling the full and complete truth about what went down at the meeting. We now know, for a fact, that they have lied about the meeting having taken place, lied about the purpose of the meeting, lied about what they knew about the woman in the meeting, and lied (if only by omission) about who was at the meeting.

All of which raises a question: Why should we believe they’re telling the truth about what happened at the meeting?

So far, the line from the Trump camp has been that the meeting involved a brief conversation about Hillary Clinton, which yielded no information, and then shifted to the topic of Russian adoptions in the United States. That’s what Veselnitskaya said as well in an interview with NBC.

But why should we believe them? They’ve lied about everything else. If they actually discussed a complex scheme of coordination between the Trump campaign and Russian hackers at the meeting, would they just admit it? Of course not, given the past track record.

Which is why this NBC scoop is so vital.

Not only does it establish that the pattern of lying and obfuscation is ongoing, but it reveals that there was at least one more person at the meeting who could corroborate (or disprove) the story about what happened. That person is also someone whose background will now almost certainly be investigated by special counsel Robert Mueller to see just how real the suspicions of his continuing connections to Russian intelligence are. If someone could substantiate that Akhmetshin really was still a Kremlin asset, that would bring the Russian government’s ties to the Trump campaign one giant step closer.

So at bottom, there’s one clear takeaway from this story: We are not yet even close to the full truth about Donald Trump Jr.’s dalliance with Russia.

Sean Illing contributed reporting for this piece.