Dr Hilary says US president Donald Trump must have had coronavirus earlier than he claims.
Appearing on today's episode of Good Morning Britain, the medical expert spoke to hosts Susanna Reid and Piers Morgan about his theory.
The 67-year-old says it 'doesn't make any logical sense' nor 'add up' that the US president contracted coronavirus at the time he claims he did.
"It seems unlikely that his symptoms began Thursday evening of last week because it's all happened so quickly." He said.
It comes as staged a dramatic return to the White House after leaving the military hospital where he has been receiving an unprecedented level of care for Covid-19.
He said the nation should not fear the virus that has killed more than 210,000 Americans, saying: "Don't let coronavirus dominate you."
Dr Hilary added: "He was in hospital with apparently low oxygen levels... and given a cocktail of antibodies and other drugs as well, and then out of hospital by Monday."
"It just doesn't really add up, it doesn't make any logical sense."
"So one suspects he had symptoms before Thursday evening and maybe was tested before that - we just don't know, we can't believe anything that comes out of the hospital over there, or from the government there.
"And it just leaves you wondering... he's in total denial about the dangers of covid"
