While 10 of the bodies were found hanging from a ceiling with their eyes and mouths covered, an elderly lady was lying on the floor.
Police said there were no bullet marks on the bodies of seven women and four men. The police, in their initial investigation, suspect it to be a case of mass suicide.
"It is a tragic incident".
New Delhi Chief Minister Arvind Kejriwal, who visited the scene, called the incident "tragic". The family was into plywood business and they were staying in the locality for the last 20 years, the locals said. The bodies have been sent for post-mortem and the mobile phones of the deceased have been taken into custody.
"We are investigating all possible angles including suicide, foul play". According to initial reports, all of them were from the same family.
He found the bodies and informed police.
The family included two brothers, their two wives who had two teenage sons and two teenage daughters each, also, their aged mother, sister and her child were found dead.
Every morning, their shop would open by 6, but when it didn't till 7.30 today, a neighbour went to check on the family.
Their bodies were hanging from an iron grill ceiling, broadcaster NDTV reported. I don't think they committed suicide.