CCTV footage appeared to show a security guard at a hospital in Buenos Aires, Argentina welcoming an invisible patient to reception and leading them to a doctor's office.
After a while, when he checked to see where the "woman" had gone, scared medics told him the only patient with that name had died the day before.
The spine chilling video footage displayed the security guard getting up from his chair as if to greet someone at the door ahead of letting them into the lobby.
It then looked as if the guard was speaking to the invisible visitor and offering them a wheelchair before they apparently went to the doctor's office on foot.
As maintained by the security guard, an elderly woman supposedly arrived at the hospital asking to see a doctor shortly after 3.30 am on November 11.
Watch the video below:
However hours later, the concerned hospital staff noticed she hadn't left the doctor's office and notified medical practitioners.
But dumbfounded doctors said they hadn't come across any patients coming or going, El Clarin reports.
When they asked him for the details of the woman patient, he told them her name - and medics were left shocked as she had passed away the day before.
A spokesperson for the private hospital said the bizarre incident is under investigation - but they think the security guard welcomed the "invisible patient" as a prank.
A spokesperson for the health care centre said the automatic door was spoiled and opened by itself more than a dozen times during the guard's working hours.
"It is the door to one of the entrances that is open after hours, it is the entrance to see the duty doctor," they told local media.
"As it was broken, it opened by itself 28 times during the 10 hours between Thursday night and Friday early morning."
They further added: "There is no entry record of any person at that time.
"This gentleman pretends to be writing something, but when you go to the registry, no one appears.
"No one entered and no one was registered either.
"But everything is under investigation."
According to the health care centre, the guard seen in the CCTV footage didn't even write anything down on his clipboard when the supposed "ghost patient" arrived.