A brief clip that is now going viral shows Lee in the moments before the live telecast was cut, where he is seen abruptly pausing his speech as a look of surprise crosses his face.
His body then begins to sway slightly to the right before the camera cuts to a gasping audience. The feed then ends abruptly
Just seconds earlier, the Prime Minister had been smiling and speaking to the audience, with no signs of illness or discomfort.
From the clip, it seems that what had overcome Lee happened suddenly and without warning, as he appears to open his mouth slightly to say something but finds himself unable to.
Social media was immediately abuzz with speculation as to what could have happened to the Prime Minister, with his office claiming that he had been “taken ill”, adding that his condition was “not serious”.
Lee’s office also confirmed that he was well enough to resume his speech, scheduled at 10.40pm.
In a tweet from his personal account, his staff also denied that he had suffered a stroke.
“PM was feeling unsteady because of prolonged standing, heat and dehydration. His heart is fine and he did not have a stroke,” it said.
Lee later resumed his speech at 10.40pm.