The accused, identified as Hemant Kumar, was a research scholar at IIT-Guwahati from where he was expelled in 2017 for harassing the 26-year-old complainant, a resident of Mumbai

Mumbai Crime: IIT scholar who stalked woman for 5 years held in Bihar
A 30-year-old man has been arrested from Bihar for sending obscene and threatening emails to a PhD scholar at Indian Institute of Technology Bombay, the Powai police said on Monday. The accused, identified as Hemant Kumar, was a research scholar at IIT-Guwahati from where he was expelled in 2017 for harassing the 26-year-old complainant, a resident of Mumbai.
Kumar first saw the woman in the lab of Ranchi Research Center where they studied between 2015 and 2016, the police said. He started stalking her and messaged her on Facebook.
"The complainant started receiving vulgar messages on her Facebook messenger after which she blocked the account," said a cop. He then created different accounts and harassed her.
After constant harassment, she informed a professor at the lab who warned Kumar. However, he did not stop. When, in 2017, the victim joined IIT-Bombay, she again received vulgar emails from different IDs, the police said. Kumar, who got into IIT-Guwahati the same year, sent messages to her batch mates too. He also threatened to commit suicide and blame her for his step.
The victim filed a complaint with IIT's women's cell when he started harassing her friends too. This led to his expulsion from IIT-Guwahati. According to police, Kumar used nine different email IDs and five phone numbers to harass her. 
The victim, who received messages from Kumar even when she was in Australia in 2017 and 2018, filed a police complaint on returning home in April 2019. The police tracked him to Purnia in Bihar and arrested him on Saturday under IPC Section 354 (outraging modesty of a women) and relevant sections of IT act, said a senior officer. He was produced in court on Sunday.