The incident took place over a decade ago and the girl, who is now 25, has taken her case to the European Court of Human Rights. Her stepfather was acquitted by the Swedish court of appeal in 2007 on charges of sexual molestation arguing that he never intended his stepdaughter to know about the covert filming.
Following his acquittal by the Swedish court of appeal (hovrätt) six years ago the case was not taken up the Swedish Supreme Court (Högsta domstolen).
The girl has always maintained that her right to privacy had been violated by her stepfather and the Swedish courts failed to protect that right.
As a result she has taken her case to the European Court of Human Rights in Strasbourg. Last year her case was referred to the Grand Chamber under the title of 'Case of E.S. V Sweden'.
The girl's identity has not been disclosed.
In a summary of the case published on the European Court of Human Rights website it says the incident took place in September 2002 when the girl was 14 years old.
"She discovered that her stepfather had hidden a video camera in the laundry basket in the bathroom. The camera was directed at the spot where the applicant had undressed before taking a shower.
"The applicant explained that on the relevant day, just before she was about to take a shower, her stepfather had something to do in the bathroom.
"When she discovered the camera, it was in recording mode, making a buzzing sound and flashing. She did not touch any of the buttons.
"Crying, she took the video camera, wrapped in a towel, to her mother. The stepfather took the camera from the mother.
"Subsequently, the applicant saw her mother and stepfather burn a film, but she was not sure whether it was a recording of her," according to the summary of the case.