Donald Trump dictated a letter which stated he had "astonishingly excellent" health during the election campaign, his former doctor has claimed.

Harold Bornstein, Mr Trump's longtime personal doctor, said he made up the glowing bill of health on the president's orders.

"He dictated that whole letter. I didn't write that letter," Dr Bornstein told CNN.

With his long flowing hair and large glasses, the medic became a colourful character in Mr Trump’s 2016 campaign for the presidency.

The December 2015 letter issued under his name declared that Mr Trump would "unequivocally" be "the healthiest individual ever elected to the presidency".

"Mr Trump has had a recent complete medical examination that showed only positive results," said the letter.

"Actually, his blood pressure, 110/65, and laboratory results were astonishingly excellent. His physical strength and stamina are extraordinary".

It went on to state: "If elected, Mr Trump, I can state unequivocally, will be the healthiest individual ever elected to the presidency".