In the third such incident in the last 48 hours, a youth hailing from the northeast was found dead in South Delhi's Munirka area on Thursday night.
Initial investigation has revealed that the youth was drunk at the time of the incident.
He fell from the staircase and sustained serious injuries, a police official said on Friday.
"It seems that he succumbed to the injuries he sustained in the fall. We have moved the body for postmortem. It will reveal the actual cause of death," said a police official.
A case has been registered and further investigations are on, police said.
On Wednesday night, a 33-year-old PhD scholar from Manipur was found brutally murdered with his neck slit with a knife in south Delhi's Kotla Mubarakpur area.
Keashung Zingram Kengoo had completed his PhD from the Tata Institute of Social Sciences. He had come to Delhi just a month ago and was searching for a job.
Another 23-year-old youth hailing from Manipur was found dead under mysterious circumstances at his home in South Delhi's Malviya Nagar on Thursday