(If you feel suicidal or know someone in distress, please reach out to them with kindness and call these of local emergency services, helplines, and mental health NGOs.)
According to embassy sources, the deceased - identified as Deepak Singh - allegedly shot himself with his rifle at around 9 am within the embassy premises.
The body has been sent to the Tribhuvan University Teaching Hospital, Maharajgunj, for post-mortem, according to the police. The reason behind the suicide is not yet known. The security guard hailed from Uttarakhand.
"He was on duty when the incident took place," The Kathmandu Post newspaper quoted an embassy official as saying.
A team of Nepal Police visited the Indian Embassy after it informed the Nepali law enforcement agency about the incident, the report said.
Sources said the Indian Embassy is conducting an internal investigation into the incident as it took place on its premises, My Republica newspaper reported.
In January 2005, two security guards were killed and another injured in an "accidental firing" on the Indian Embassy premises.