Donald Trump fans think Hillary Clinton ‘used a body double’ after her 9/11 memorial 'collapse'

Her stumble was taken as 'proof' by opponents she is seriously unwell

Ms Clinton walks, smiling and unaided, out of her daughter's apartment shortly after the stumble (AFP/Getty Images)

Just when you thought the Hillary Clinton conspiracy theories couldn't get any more outlandish, up pops another one.

On Sunday, the Democratic candidate suffered a well-publicised "stumble" which her campaign team says was brought about by overheating but was later clarified to confirm she was suffering from pneumonia.

Her stumble was taken as "proof" by some of her opponents that she is seriously unwell and is unfit to be president.

Mrs Clinton has already been at the sharp end of some claims about her supposedly failing health - brain cancer, autism and multiple sclerosis have all been bizarrely claimed.

And now Trump supporters have claimed that she didn't recover from her fall and pictures of her later on that day outside her daughter's appartment were, in fact, images of a body double.

She was seen leaving her daughter's flat and waving to the crowd, before posing for a photograph with a young girl.

When a reporter asked her if she felt better, she replied: "Yes, thank you. I'm feeling great. It's a beautiful day in New York."

Ms Clinton's doctor said she was being treated for pneumonia and was "recovering nicely".

But conspiracy theorists claim Ms Clinton's health is far worse than reported and she has resorted to using a body double.

They pointed to perceived differences between photos of the presidential hopeful at both events.

Others suggested the photos actually showed Teresa Barnwell, a well-known impersonator of Ms Clinton.

However, Ms Barnwell later tweeted to say she was not in New York City and was "just messin' with your crazy conspiracy minded little heads," after she posted a photo of herself outside Chelsea Clinton's building.

Mr Trump has now promised to release a detailed report on his state of health.