Indrani Mukerjea, the former owner of a TV channel along with Peter Mukerjea, was arrested in August 2015 for the murder of 25-year-old Sheena Bora, her daughter from her first marriage.
Three months later, Peter Mukerjea also was arrested and accused of helping Indrani in the murder.
He had argued that he was abroad on the day that Ms Bora was reported to have been killed after being abducted and strangled. Peter in his defence had said that he has believed Indrani's explanation that Sheena Bora had gone abroad.
The phone call that driver Shyamvar Rai spoke about in a Mumbai court is important because it links him to the crime.
In its charge-sheet, the CBI had alleged that Indrani Mukerjea kept Peter informed on the phone about the selection of place for disposal of Sheena's body during the recce and on the day of the murder, 23 April 2012.
Sheena Bora was allegedly killed inside a car by her mother, with help from her second husband Sanjeev Khanna and her driver Shyamwar Rai. Investigators say Indrani was furious about Sheena's relationship with Rahul Mukerjea - Peter Mukerjea's son from an earlier marriage. Indrani later told friends that Sheena - whom she had always presented as her sister - had shifted to the US.
The relations between Indrani and daughter Sheena were said to be strained, particularly since Indrani refused to acknowledge Sheena as her daughter in public and introduced her to the world as her sister.
Last year, Indrani also asked Peter Mukerjea for a divorce and in November, accused Peter of having conspired ad abducted Sheena to make her "untraceable". Peter Mukerjea, the former TV channel owner has accused his wife of "playing the victim card" and developing "a sinister plot" to implicate him.