A senior official with the Union ministry of home affairs was found dead under mysterious circumstances in the Capital's Ram Manohar Lohia (RML) hospital on Thursday night.
Doctors claimed they found the 56-year-old hanging from the ceiling fan, but the police said his lifeless body was on the bed when they reached the spot.
The victim was undergoing treatment at the hospital's private nursing home for "uncontrolled hypertension".
He was reportedly alone in the ward as his daughter had stepped out for a while.
"She went out for a while and found him hanging on her return," said a hospital staff.
No suicide note was found at the incident spot.
"It is not clear how he died, so we will wait for the post-mortem report," said a Delhi Police official.