A 19-year-old collegian allegedly committed suicide after being harassed and blackmailed in a "sextortion" case in Dattawadi in Pune, the second such instance in the city in the last few days, a police official said on Thursday.

The teen, an undergraduate commerce student, had killed himself on September 28 and his brother has told police the deceased was being blackmailed by an unknown person on social media, the official said.