Sonarpur: A youth travelled around 40km from his home in Sonarpur to Barasat and killed himself by jumping in front of a local train after a young woman allegedly blackmailed him and threatened to lodge a rape complaint against him.

Sourav Ghosh, in his early 20s, committed suicide six days ago. His family lodged a complaint with Sonarpur police station on Tuesday accusing the woman of abetting the suicide.

In a video footage apparently found on his cellphone, Sourav is heard narrating his plight and accusing the woman, with whom he had an affair, of blackmailing him.

Some screenshots found on his phone reveal that the woman had posted pictures of the youth's private moments on a social networking site and made derogatory comments about him, police said.

"A preliminary investigation has revealed that Sourav, who worked at a bookstore on College Street, had an affair with the woman. Her maternal uncle's house is near Sourav's in Sonarpur. The two first met during one of her visits to her uncle's house," an officer of Sonarpur police station said.

Sourav's family members said they came to know about their affair after he had committed suicide.

The youth was seen loitering on a platform at Hridaypur station in Barasat, around 40km from his home, before jumping in front of a speeding train on July 19 night, the police said. He died the next day at a private hospital on EM Bypass.

"Sourav is heard saying in the video, which he had recorded on his cellphone, that he had an affair with the woman. He is heard alleging that the woman had recorded his private moments secretly when he was at her house and extorted money from him," an officer said.

Investigations revealed, the police said, that the woman had placed her cellphone inside a showcase secretly when Sourav went to the washroom at her house.

"We have come across text messages on Sourav's cellphone that suggest the woman was threatening to lodge a rape complaint against him if her demands were not met," the officer said.

Sourav is heard saying in the video clip that he was tired of meeting the woman's demands for money and gifts.

His family members told the police that the woman was responsible for Sourav's death. "It appears that he was in love with the woman. But it was actually a trap laid by the woman," another officer quoted a relative of Sourav as saying.

"The woman used the recordings on her phone to blackmail Sourav. He was not his usual self over the past few days and remained quiet but we never thought he would take the extreme step," the relative apparently told the cops.

Sourav's cellphone will be sent for forensic tests.