The victims have been identified as Vikram Singh and his wife Jyoti Singh.
According to the police, victim's brother Sailendra Singh alleged that Abhinav Agrawal, a friend of his brother had visited their house. They went to rooftop to have some beer.
"I was also present when Abhinav came to the house. As Vikram and Abhinav were normal, I went to my room and slept. Around 3.30 p.m. I woke up on hearing a loud noise. When I reached rooftop, Vikram and his wife were lying in the pool of blood on the floor with several stab wounds," Sailendra said.
Sailendra said Abhinav had borrowed Rs 1.5 lakh from his brother and was delaying the repayment. "Abhinav had borrowed Rs 1.5 lakh some two years ago and was not returning the money. Vikram recently asked him firmly to return the amount," he said.
He along with cousin brother Ajay took them to sector 10 government civil hospital where doctors declared them brought dead, Sailendra said.
The police have registered an FIR against Abhinav in the twin murder case at the Udyog Vihar police station. "We are trying to find out any eyewitness to the crime," said Subhash Bokan, PRO of Gurugram Police.
CCTV footage in the locality were also being studied to ascertain the identity of killer, Bokan added.
( With inputs from IANS )