Police officer Vineet Kumar said on Sunday all of them belonged to a family and most had lived in one home in Burari village in the northern part of the capital.
All were sent for an autopsy on Sunday (local time).
A senior police officer said the victims comprised seven women and four men. They may have committed suicide after the business suffered financial losses, News18 quoted unidentified police officials as saying.More news: McConnell predicts Supreme Court nominee will be confirmed
Preliminary investigation revealed that the head of the family is running a plywood shop in the same premises. They have been living in the area for the last two decades. There was no sign of forced entry into the house either, police said.
While some were found hanging, others were lying on the floor. He raised an alarm and people called the police.
"The neighbour told us that the door usually remained closed". The police are looking to ascertain if it is a case of mass suicide or the bodies were hanged after being killed.