A transportation worker was arrested hours after a mainland student on holiday was raped in a hostel in Tsim Sha Tsui's Chungking Mansions.
The suspect, a 26-year-old Indian, is said to be seeking political asylum and has been living in the territory for several years.
The university student, 21, was visiting Hong Kong with a female friend and staying in one of the many guesthouses that provide cheap accommodation. Communal bathrooms are also a feature of many of these cheap hostels.
According to police, the student had just finished showering in a bathroom reserved for women around midnight on Saturday.
Returning to her room clad only in a towel, she was attacked, gagged and raped.
The victim screamed for help when her assailant left and her friend, in a neighboring room, called the police. All exits of the building were cordoned off as officers checked CCTV footage and conducted a door- to-door search.
The suspect, who was also staying in the building, was arrested at 4.50am.
The student was sent to Queen Elizabeth Hospital for a body check. She was accompanied by her friend.
Officers of the Yau Ma Tei Regional Crime Unit are now investigating the case.
Police said the victim had previously visited Hong Kong and usually stayed at Chungking Mansions.
The 17-story building on Nathan Road was originally a residential block when built in 1961. But with the demand for cheap accommodation, it has since become a warren of hostels, serviced apartments and curry shops.