The 23-year-old Nepali man, Debu Tamang alias Dev Bahadur, was arrested from Aya Nagar area of south Delhi.
Police said Bahadur – who was a cook – was planning to move to his hometown in Nepal.
He is accused of raping the 19-year-old girl from Assam at a guest house in DLF-1 area here on April 29.
Both the girl and the accused worked in the same guest house.
“He was planning to reach Anand Vihar bus stand in Delhi by Delhi Metro. Bahadur was arrested while he was preparing to reach the Arjangarh Metro station,” a police officer said.
The girl in her police complaint said she was raped by Bahadur in the washroom.
When she cried for help, the sweeper of the guest house came to the washroom but instead of helping her, he kept on laughing, she said.
She also alleged that she informed the woman manager of the guest house about the incident but she did not cooperate and helped Bahadur in escaping.
Over 150 people, belonging to the northeastern region, had on Friday staged a protest outside the police station in DLF-1 area over police inaction in the case.
The agitators had warned police of a bigger protest if police failed to arrest the accused.
Bahadur was on Sunday presented before the duty magistrate and sent to police custody for one day.