Dharam Singh and his wife Kamlesh, both in their forties, were stabbed to death at their residence in Chawla locality of Najafagarh this morning, police said.
Investigators suspect the motive of the murder to be personal dispute or enmity as there was no looting in the house.
"We suspect that some relatives are involved in the incident. We have interrogated some relatives," a senior police official said.