I have no idea whether or not Paul Manafort visited Julian Assange at the Ecuadorian embassy in London. But the U.K. intelligence community almost certainly knows.

While the U.K. suspended its 24-hour police guard outside the Ecuadorian embassy in 2015, Britain's MI5 security service has maintained intelligence coverage of Assange's activities. That effort includes a particular focus on who Assange has met or communicated with and what they discussed.

This is relevant in light of the Guardian's reporting on Tuesday that Manafort visited Ecuador's embassy in 2013, 2015, and in spring 2016. If true, Manafort's spring 2016 meeting with Assange would be particularly interesting.

The first question, then, is whether MI5 or another British authority would have told the Guardian about Manafort's visit. That's a hard one to judge, but I'm going to suggest it's unlikely. While Luke Harding, one of the reporters on the story, is highly respected for his national security reporting, the Guardian is not terribly popular with many in the British intelligence community because of the newspaper's reporting on Edward Snowden's leaks related to the National Security Agency in the United States.

Still, the U.K. would have paid very close attention to any Manafort visit to the embassy. After all, Russia's manipulation campaign targeting the U.S. presidential election was well underway by spring 2016. Seeing as the Russian GRU used Wikileaks as the publicizing entity for copies of Democratic National Committee emails that it had hacked, and that Manafort became Trump's campaign manager shortly after his supposed 2016 meeting with Assange, any meeting would be of interest.

That said, it's also possible that Manafort might have had a pre-existing relationship with Assange related either to Manafort's Ukrainian business dealings or some other issue.

The U.K. is best placed to know exactly what Manafort and Assange may have discussed. Bugging the Ecuadorian embassy would not be a particularly challenging task for the exceptionally capable MI5. That's not simply because MI5 is excellent at its job but because the Ecuadorian counterintelligence community isn't on a par with those of major world powers. In turn, MI5 intelligence officers working alongside what MI5 calls "covert technical operations specialists" would have a good chance of bugging the embassy or using other technical measures to listen to what was going on inside. The key here is that there are a range of exceptionally innovative ways to gain access to protected facilities. Indeed, human-technical operations is almost James Bond-esque!

Of course, it's also possible that MI5 never gained access to the embassy. Even in that, however, the British would retain surveillance logs on who was coming and going. Put simply, the U.K. government knows full well whether Manafort ever entered the embassy to meet with Assange. Due to the intimate U.S.-U.K. intelligence relationship, the U.S. government almost certainly also knows.