LONDON: A photo of a sick boy sleeping on a hospital floor because no beds were available has become one of the defining images of Britain’s bruising election campaign.

It forced Prime Minister Boris Johnson onto the defensive and ignited a fierce online debate over whether it was real or fake.

The boy, 4-year-old Jack Williment-Barr, had been admitted to Leeds General Infirmary last week with suspected pneumonia. He eventually was diagnosed with flu and tonsillitis and then discharged, but not before he was photographed lying on the floor cushioned by a coat with an oxygen mask nearby. A red coat served as a blanket.

The story was splashed across Monday's front page of the left-leaning national tabloid Daily Mirror, including the photo of Jack in his Spider-Man top under the headline, "Desperate."

The photo and subsequent posts swept through British social media like a firestorm, injecting an unpredictable and explosive jolt into the intensifying political war of information just days ahead of Thursday's election.

Jack's story came to national attention in a newspaper article critical of the Conservative Party's cuts to the UK's national health service.

But then a Facebook post appeared, promoting a counternarrative.

"Very interesting. A good friend of mine is a senior nursing sister at Leeds Hospital," the post began, and went on to spin the tale that the photo of Jack was a setup for the cameras.

It soon was shared thousands of times. Disinformation experts noticed interesting similarities among the posts. For starters, Facebook and Twitter users shared the exact same language of the post by either copying and pasting the wording or taking screenshots of it.

They tried to bring it to the attention of "influencers" with big Twitter followings by tagging prominent users like former soccer stars Rio Ferdinand and Gary Lineker, as well as Johnson, in an apparent attempt to amplify the message, said Alastair Reid, digital editor at First Draft, a nonprofit group that investigates misinformation.

There also were attempts to tag British TV journalists Robert Peston and Laura Kuenssberg, who were duped hours earlier into sharing a separate fake story about a government minister's aide being punched that apparently was spread by Conservative party insiders, Reid said.

The post also was shared widely in public Facebook groups advocating for Brexit, the Conservative party's main cause at the election.

A woman whose Facebook account was used to publish a claim that the original story was fake told The Guardian newspaper that she had been hacked.

"I am not a nurse and I certainly don't know anyone in Leeds," the woman told the Guardian, which said it was withholding her name because she said she had received death threats. The newspaper said she tried to report the hack to a fraud advice service.

A woman who had sparked claims that the viral photo of Jack sleeping on a hospital floor was staged has spoken to #Newsnight.

She insists she was an innocent party and her son says it had nothing to do with him. pic.twitter.com/0TStJQz7KM

— BBC Newsnight (@BBCNewsnight) December 10, 2019

The Associated Press was unable to contact the woman or Jack's mother.

But whether or not the account was hacked, the big question was how the claim got "pushed into all these different groups and front of all these people, and who was spreading it? And that's something which at this stage is hard to identify," Reid said.

The only people who have that level of information are Facebook and Twitter, he added. Facebook didn't reply to a request for comment.

Twitter investigated the accounts that were involved in spreading the message and found no signs of platform manipulation or automated activity.

"We're committed to improving the health of the public conversation on our service, particularly during elections," Twitter said in a statement. "To this end, platform manipulation is strictly against the Twitter Rules. We will take aggressive enforcement action if we identify this behaviour on our service."

Reid called it "a concerted effort to put it in front of a very wide audience. But who exactly is doing that and whether or not that is coordinated is still not clear."

The episode highlights how easy it has become to elevate hot-button issues through social media. The combination of Britain's beloved National Health Service and a sick child may have been enough to arouse strong feelings across the country.

"Emotion is the currency of social media, whether it's outrage or whether it's love or whether it's humor. That's the fuel that powers a viral post," Reid said.

And with two days until a national election, at a time when trust has become a huge issue, "this plays into some of those existing narratives and people are taking advantage of that to sow misinformation," he said.

Britain's election laws were largely written before the dawn of the internet, with online campaigning and political messaging mostly unregulated and open to exploitation by a new generation of activists who grew up with the technology.

Similar loopholes were exploited by Russian trolls during the 2016 US presidential election.

The editor of The Yorkshire Post, which published the story that first appeared in the Yorkshire Evening Post, stood by its reporting and posted on his Twitter feed a response he wrote to a reader left bewildered by the claims and counterclaims.

"I do hope we are not too late to help people like her, so unfairly manipulated and discombobulated by cynical social media messaging driven by dark forces," editor James Mitchinson tweeted.

@JayMitchinson calls out the constant flow of subterfuge during this GE campaign and suggests what needs to be done, to avoid this happening in future elections.@BBCWorldTonight #GE2019 pic.twitter.com/j8HWI3eN3r

— Martin Cooper (@mpc_1968) December 11, 2019

Matt Walsh, who researches digital political communication at the University of Cardiff, called the social media storm "the nadir" of the campaign.

"The issue here is that material is being put in the public domain through some very dark networks," he said. "False stories are getting out there and exploding in social media. And in the end, real, people are being affected."

Details of The Yorkshire Post's story were confirmed by a written statement issued by Dr Yvette Oade, chief medical officer at Leeds Teaching Hospitals NHS Trust that included an apology to Jack and his family.

Walsh said people slinging mud online before the election "may not be connected to the parties, but they are putting out misinformation in hopes of taking people in."