Pushpawati (84) and Sarita Devi (55), grandmother and aunt of Bhavish, were found dead inside their home at Sher-e-Punjab colony in Badowal locality here on January 29.
The family's driver Sukhpal Singh alias Bagga, a resident of nearby Flewal village, has been arrested for the double murder, Commissioner of Police, Ludhiana, Paramraj Singh Umranangal told reporters.
Sukhpal told police during interrogation that he went to the residence of the victims and demanded Rs 5,000 from the ladies to get married, Umranangal said.
The two victims, who are the mother and wife of a noted city cardiologist Dr Rakesh Aggarwal, were found in a pool of blood by their domestic help Pooja, who called the police.
The police earlier had detained Pooja for interrogation but released her following protests from other domestic workers.
The police said some gold ornaments which the two victims were wearing were also missing and probe was on to recover them.