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       image captionStock image of an Indian jail

       Authorities in India are investigating a case where a 15-year-old girl was repeatedly gang-raped for around nine months, said local media reports.

       Police in the city of Mumbai have arrested 28 people in connection to the alleged rapes, which began in January.

       Local reports said it began when the girl's boyfriend raped her and filmed the incident.

       He and his friends then reportedly used the recording to blackmail her into having sex with them.

       Authorities said the gang-rapes happened in different suburbs of Mumbai, including Dombivili, Badlapur, Murbad and Rabale.

       The girl finally reported the case to the police on Wednesday night. News outlet NDTV said the girl had named 33 attackers in total, and that she knew almost all of them.

       Since the infamous 2012 bus gang-rape of a woman dubbed Nirbhaya, which led to global outrage, India has introduced tough laws to deal with crimes of sexual nature.

       But despite the increased scrutiny, it still remains a serious problem.

       In 2020, India's National Crime Records Bureau recorded 28,046 rape cases - or nearly 77 cases a day.

       Campaigners say the actual numbers are much higher as many are not even reported, as rape is still seen as a taboo subject by many in Indian society.

       media captionDelhi Nirbhaya rape death penalty: How the case galvanised India