The accused, identified as Faizan was arrested from near Lajpat Nagar Metro station in southeast Delhi after the victim reported the matter to police.
The 30-year-old woman had been getting several lewd messages from September 18 on her mobile. The sender had not just sending pornographic videos but was also pressurising her to enter into sexual relations with him.
"When the woman called him back in order to check whose number it was, the accused started to threaten her of raping her if she did not give in to his demands for sexual favours," said a police official.
Faizan told police during interrogation that he had spotted the woman at the Nizamuddin Dargah few times and had procured her number somehow.
The accused is a taxi driver and a resident of Nizamuddin area. A case under appropriate sections was registered at Lajpat Nagar police station against him, police said.