The main accused Pinki Tulsi Gupta and the complainant Rubi Vidyaratan Verma worked at a beer bar at Mira Road and visited each other frequently, District Superintendent of Police Anil Kumbhare said today.
Some days ago, they had a petty quarrel, after which a conspiracy to abduct Verma's son was hatched, police said.
On January 24, Pinki, Kiran Gupta and Tinku Singh abducted the boy, Ayush.
Later, Verma got a call from an unknown person who demanded Rs 26 lakh for the release of her son. Police traced the call to a PCO in Kolkata, so a team was sent there.
Pinki's mother Rinidevi (60) too has been arrested, as she was the one who took the boy to Kolkata, police said.