Raja's mother Uma Raghuvanshi claimed her daughter-in-law had made all the bookings of travel and stay but skipped her return ticket.
Uma says Sonam may have extended their honeymoon trip to Shillong, the capital city of Meghalaya, but she didn't share the details of the journey with either of the families.
"Sonam booked the tickets for the trip, and she may have extended the trip to Shillong, as my son did not know about the region. Her mother told that they visited Shillong last year," the victim's mother said as quoted by NDTV.
The Meghalaya Police on Monday arrested four people including the wife of the Indore-based businessman in connection with the murder case.
As per police, Sonam had hired killers to murder Raja.
Police said Sonam surrendered in Uttar Pradesh's Ghazipur while three others were arrested during raids.
The arrested men reportedly admitted to the police that they were hired by Sonam.
Sonam's father has claimed his daughter's innocence and accused the Meghalaya Police of foul play.
Her father Devi Singh said as quoted by India Today, "My daughter is innocent. I trust her completely. She cannot do this. They got married with the consent of both families. The Meghalaya government has been lying from the beginning."
Raja and Sonam went missing on May 23 during their honeymoon in Meghalaya.
While Sonam remained missing, Raja's body was found in a gorge at Sohrarim near Cherrapunji.