India, June 15 -- Five days after a four-year-old boy led his family to a cab containing the blood-soaked bodies of his mother and a cab driver on the Badlapur-Neral highway, police have said the murder-suicide was allegedly triggered by the collapse of a three-month extramarital relationship.

Investigators said the cab driver, Ganesh Shinde, had allegedly planned the crime after the married woman stopped responding to his calls and blocked his phone number, bringing their relationship to an abrupt end.

The case came to light on Thursday evening when the woman's four-year-old son, who was inside the vehicle during the attack, stepped out of the cab near Joveli village off the Neral-Badlapur Road and sought help from a passing motorcycli...