A family in Bangalore was at home on a Friday night late last month when they heard a knock at the door.
Four men outside said they were from the police - though they were not in uniform - and allegedly forced their way in, claiming they wanted to search the house because they had been told marijuana was stored inside.
The men were armed with knives, the police said, and attacked a 25-year-old woman, her husband, and his parents.
Though the family initially reported a robbery, the four suspects, when caught a few days later, allegedly confessed that two of them had raped the woman and that her relatives could not rescue her because they were tied up. Medical tests confirm the sexual assault.
"During the course of interrogation, they revealed that along with robbery they have sexually assaulted the lady also. We have contacted the victim's side and persuaded them to give the complaint," said Alok Kumar, a senior police officer.
The four suspects are all 21 years old, said the police, and were wanted for a series of thefts.