The eyes and mouth of the 10 members, found hanging were covered with cloth and taped, while a 77-year-old woman, found dead on the floor, was not blindfolded, the police said, adding that the hands and feet of the children were tied.
The police found some hand-written notes during a search of the house, which, they said, suggest the family might have been observing some religious rituals.
"We have found handwritten notes detailing how hands and legs are to be tied and are quite similar to the manner in which the bodies of 10 persons were found. They are exhaustive notes and we are studying them," said Joint Commissioner of Police (Crime) Alok Kumar.
Another officer said the notes were found in a couple of registers and are quite exhaustive. They talk about how one can overcome fear by covering one's eyes and mouth, how one can attain salvation and how the human body is temporary but the soul always continues to live on.
"The notes say if a group of 11 people follows these rituals, all problems would ease out and they would attain salvation. Some notes have dates on which they were written while others didn't have it. All the notes talk about reaching the end and gaining peace," said one of the investigators.
While a murder case has been registered, the police suspect the deaths to be a case of suicide pact.
"It is possible that the elderly woman was strangulated since she was not in a condition to climb the stool. We are probing whether the children were killed or were convinced to take the extreme step," said the other officer.
The police are also probing whether the family was into black magic or was following any godman.
The deceased were identified as Narayan Devi, who was found dead on the floor, her daughter Pratibha (57), her two sons Bhavnesh (50) and Lalit Bhatia (45).
The other victims included Bhavnesh's wife Savita (48) and their three children - Meenu (23), Nidhi (25), and Dhruv, aged 15.
Lalit Bhatia's wife Tina (42) and their 15-year-old son Shivam were also among those found dead.
Pratibha's daughter Priyanka (33), who was engaged last month and would have married by the end of this year, was also found hanging.
Locals, however, said that even though the family was religious, they never saw anything suspicious.
"They would chant 'Gayatri Mantra' and worship gods once during morning and once in the evening. We never saw any 'tantrik' or godman visiting their house. They were helpful and humble," said one of the neighbours.
Devi's grandson, Ketan Nagpal, said the family members were killed and someone was trying to mislead the investigation.
"We have not been informed about the notes. In this day and age, who follows such things? They were killed and the police have to find the accused," he said.
The neighbours also said that the victims family members regularly used to write one or the other religious 'shlokas' in Hindi on a board outside their house.
The post-mortem examination of the bodies is being carried out, the police said., adding that it will clear only after autopsy if one of them killed the rest and then committed suicide or was it a suicide pact.
"We will also be speaking to Bhavnesh's elder brother Dinesh and sister Sujata to know about various religious practices followed by them," said the investigator.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)