The Senate Intelligence Committee has asked WikiLeaks founder Julian Assange to testify privately about Russian interference in the 2016 election. We know this because WikiLeaks, well, leaked the letter.

The intelligence panel won’t verify whether the request is real. But if it is, and Assange officially agrees to be interviewed about possible collusion between Russia and Donald Trump’s presidential campaign, it would be a big deal.

Here’s why: After members of Russia’s military intelligence unit hacked and stole emails belonging to the Democratic National Committee (DNC) and Hillary Clinton’s campaign chair John Podesta, they handed them over to WikiLeaks. Assange’s organization then slowly disseminated them to the public, keeping the emails constantly in the news cycle during the 2016 presidential election.

Assange, who’s wanted on charges of rape and has avoided extradition by hiding in the Ecuadorian Embassy in London, denies his organization worked with Russia. “Our source is not the Russian government,” he told Fox News’s Sean Hannity in January 2017.

BREAKING: US Senate Intelligence Committee calls editor @JulianAssange to testify. Letter delivered via US embassy in London. WikiLeaks' legal team say they are "considering the offer but testimony must conform to a high ethical standard". Also: https://t.co/pPf0GTjTlp pic.twitter.com/TrDKkCKVBx — WikiLeaks (@wikileaks) August 8, 2018

Despite this, WikiLeaks’ ties to Russia have long been known, even before the last presidential race.

As my colleague Matthew Yglesias noted, the release of the emails “also seemed strategically timed — the [DNC emails disrupted efforts to create a show of unity between Hillary Clinton and Bernie Sanders at the beginning of the Democratic National Convention, while the Podesta emails were released right after the infamous Access Hollywood tape.”

That’s not all: Former Trump campaign adviser Roger Stone had private contact with WikiLeaks and claimed he had inside knowledge about Assange’s plans to release damaging information about Clinton.

In one instance on August 4, 2016, about a week after WikiLeaks posted the DNC emails, Stone emailed his longtime associate Sam Nunberg: “I dined with my new pal Julian Assange last nite.” (Stone has since said this was just a joke.)

That same day, Stone appeared on the Infowars radio show and said he thought Assange had “proof” of the Clintons’ corruption and would “furnish” that proof “to the American people.” He also mentioned that he spoke with Trump the day before, raising questions of what he might have told Trump.

But Stone suddenly began expressing doubt that Russia provided the DNC information to WikiLeaks — which contradicts what he had previously said, CNN’s Andrew Kaczynski and Christopher Massie reported in April.

Stone denies any collusion with WikiLeaks.

Surely Senate Intelligence Committee staffers will want to know more about all of these matters. But whether Assange — who reportedly believes all information should be public — will tell investigators exactly what he knows is still an open question.