The woman, a resident of West Mambalam, had left her home on May 13 without informing her family. Her parents traced her to Mambalam Railway Station and brought her home on May 18, according to the police.

The next day, she fell ill and was taken to Kasturba Gandhi Government Hospital in Triplicane. A medical examination revealed she had been sexually assaulted, after which the police were alerted. The police investigation found the woman was active on Instagram and had a habit of leaving home for days before returning.

On May 13, she met Imran (30) of Chintadripet, whom she knew through social media. He offered her a ride on his two-wheeler and took her to a secluded stretch behind the Marina Beach swimming pool, where he allegedly sexually assaulted her. He dropped her off at Fort Railway Station early on May 14.

From there, she travelled to Mambalam Railway Station, where an autorickshaw driver helped her get a job at a T Nagar clothing store and she stayed at a hostel. The woman then left the hostel and travelled by train to other parts of the state, where she met her social media acquaintances.

Her phone was allegedly robbed by them after which the woman returned to the city. On Tuesday, acting on a tip from a family friend, her father found her at Mambalam Railway Station and brought her home.

The police registered a case and arrested Imran. He was produced before a magistrate and remanded in judicial custody. As the offence occurred at Marina Beach, the case was transferred to the Triplicane All Women Police. Officers are working to trace other men who may have abused the woman during her travel.