Jeremy Corbyn set off a political row at a press conference on Wednesday when he unveiled leaked government documents about international trade negotiations.
Only eight days earlier, Mr Corbyn had brandished a heavily redacted version of the same documents during the ITV party leaders debate, saying they were evidence of a government cover-up.
Thick black lines covered much of the text that detailed discussions between US and British officials about drug prices in a possible trade deal after Brexit.
Debate rages on about what the documents actually mean. The uncensored versions first appeared online more than a month earlier, but initially gained very little attention.
The ultimate source of the leak remains a mystery, but here's what we know.
The Reddit post
On 21 October, somebody with the user name "gregoratior" posted the documents on Reddit.
"I suspect that this publication will make some noise," the post began.
Nothing could be further from the case. Despite appearing on a Reddit group or "subreddit" with nearly one million subscribers, the thread attracted just five comments. Almost nobody seemed to notice.
Two days later, somebody who appeared to be the person or persons behind the Reddit post embarked on a campaign to try to get someone - anyone - to pay attention.
A Twitter account was created: @gregoratior. It started responding to tweets using a repetitive message, and including a link to the original Reddit post.
The first accounts mentioned in these tweets were the official accounts of the Labour Party, the Labour press office, and shadow chancellor John McDonnell:
Over the next several days and weeks, @gregoratior fired messages at politicians, journalists, activists and conspiracy theorists - even celebrities like Bette Midler and businesses like book store Waterstones. All of the messages were virtually identical.
Links to the documents also popped up in murkier places.
Someone using the name "Wilbur Gregoratior" and the same profile picture as the Twitter account posted on BeforeItsNews.com, a conspiracy-heavy site which encourages readers to upload their own stories.
Prior to the post about the leak, "Wilbur Gregoratior" had uploaded three other stories to the site, all in early October.
- "The Democrats' Impeachment Attempt Against Trump Is A Huge Mistake" - copied and pasted from a pro-Trump blog called Moon Over Alabama.
- "China's Anniversary Parade Reveals New Weapons That Will Influence U.S. Strategies" - another post copied from the same blog.
- "Twitter Executive for Middle East Is British Army 'PSYOPS' Soldier" - again, a direct lift of a story, but this time from the news website Middle East Eye.
The Reddit link was also posted on message board 4chan four times in quick succession on 23 October, and again the following day.
After lying dormant since 11 November, the @gregoratior Twitter account was suspended on Thursday. The BBC understands that this was because it was violating the platform's anti-spam policy.
"The only content it's tweeted shared the leaks," says Ben Nimmo, head of investigations at social media analytics company Graphika. "That makes it look like an account set up with the sole purpose of amplifying the leaks."
So are there any further clues about who is behind the Gregoratior Reddit account which originally posted the leaked documents?
The account was created more than two years ago, but only started posting in September 2019. Since then, Gregoratior has made more than 20 comments on other people's posts, mostly on politics and current affairs topics.
"It s funny but that excites me," read one, on a thread titled "Reporters Should Stop Helping Donald Trump Spread Lies About Joe Biden and Ukraine."
"I mean, Ukraine is thousands miles away but news these days made it much closer." the comment continued. "It s really fun to watch how easily mass media can turn every point on the map into a hotspot of the US politics."
The last post from Gregoratior came on 11 November - it was again trying to draw attention to the original post about the leaked documents.
Then came the ITV debate on 19 November. During the broadcast, Mr Corbyn produced heavily-redacted versions of the documents, and announced that they were the result of a Freedom of Information request.
"You're going to sell our National Health Service out to the United States and big pharma," Mr Corbyn said, after pointing to the mostly blacked-out pages and criticising the lack of transparency.
Boris Johnson replied: "This is an absolute invention. It is completely untrue."
Global Justice Now (GJN) is a campaign group that originally lodged the Freedom of Information request in an attempt to force the government to release the documents.
GJN spokesperson Jonathan Stevenson says that after the debate, the organisation was contacted via email and alerted to the presence of the uncensored documents on Reddit. The group was still reviewing the leaked papers when Mr Corbyn held his press conference on Wednesday.
BBC Trending attempted to contact Gregoratior via Reddit, Twitter and email, but we have not received a response.
A Labour Party spokesperson declined to comment on the source of the leak. We also contacted Reddit, but have not received a response.
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