The Pattinapakkam police on Saturday arrested a 52-year-old man working in a private firm for sexually harassing a woman colleague. The accused has been identified as R. Viswanathan, 52, of Madipakkam who was arrested following a complaint from his 37-year-old colleague in a private firm in Mylapore. The police said the accused sent abusive email to her besides sending similar mails continuously to other colleagues damaging her character.