Police said the apparent dispute over the phone charger was considered as one possible motive but the exact cause of the attack could not yet be confirmed and that other theories were being investigated.Family members had complained that the man had also been stalking her, according to some local media reports.Local media in India are reporting that police are struggling with the issue because the callers are anonymous and often use untraceable SIM-cards.Police have made no arrests, years after it came to light, and go after the shops instead of the cold-callers.Locals are said to have told police Mr Chaurasiya was the girl's neighbour and that she had borrowed a mobile phone charge belonging to his brother.It is claimed he became enraged when she refused to return it.

Filmmaker Nawneet Ranjan founded the Dharavi Diary project, which teaches young girls in the slum to code.

The result of their involvement in the program can ultimately lead them to better education and more employment opportunities.

“A lot of girls in the neighbourhood don’t get the chance to use computers and laptops,” Ranjan told Mashable.

The incident sparked outrage on the streets of India and shone an international spotlight on sexual violence against women in the country.

Almost three and a half years later and after much deliberation, the government is in the process of implementing measures aimed at making public transport safer for women.