Clinton diagnosed with pneumonia before 'fainting' at 9/11 memorial

Hillary Clinton was diagnosed with pneumonia before her apparent 'fainting' at a 9/11 memorial service, her doctor has said.

The Democratic presidential candidate's team initially explained her early exit from the event by saying she was simply "overheated".

Hours later, it was announced that she had been advised to rest after being diagnosed with the lung infection on Friday but was now "recovering", in a statement from her doctor.

A campaign official said on Monday that Mrs Clinton's planned fundraising trip to California had been cancelled as a result of her pneumonia diagnosis.

It comes after Donald Trump's team and his supporters repeatedly made unsubstantiated claims that she has health issues and is physically incapable of being president.

Mrs Clinton had arrived at the memorial service in New York at around 8.15am but left suddenly around an hour-and-a-half later.

Multiple sources told NBC that Mrs Clinton fainted, while there were also claims that one of her shoes fell off as she entered a car to leave.

An unverified video purportedly taken at the event appeared to show Clinton collapsing as she prepared to leave.

Mrs Clinton's physician, Dr Lisa Bardack said that the Democrat had initially "been suffering a cough related to allergies" which had developed into pneumonia by Friday night.

Mrs Clinton's team had earlier said that she "overheated" while paying her respects but was now feeling "much better".

She told reporters she was "feeling great" as she left her daughter's apartment, where she had gone to rest after leaving the service.

Mrs Clinton suffered a concussion after becoming dehydrated and fainting in 2012 while secretary of state.

Her health has continued to be the subject of conspiracy theories, which have been embraced by Mr Trump’s team, during the current race for the White House.

Mrs Clinton has insisted she is unconcerned by the rumours but this latest episode will likely fuel more speculation over the issue.

Right-wing news outlets and commentators have variously claimed that she has suffered a stroke, struggles to walk and has a bodyguard carry around a syringe containing anti-seizure medicine.

In a letter released by her doctor in July, Mrs Clinton was described as being in "excellent health" and "fit to serve" in the White House.