Chris Brown has been sued by his housekeeper after her sister was attacked by the rapper-singer's dog.

According to a lawsuit filed in Los Angeles Superior Court, Patricia Avila and her sister Maria were attacked by Brown's dog when they were cleaning his house on December 12 last year, reports aceshowbiz.com.

The lawsuit added that prior to the attack, his dogs had been kept in another part of his property, which prevented the housekeepers from coming in contact with the animals.

On the day of the incident, one of the dogs, described as a Caucasian shepherd, was in the backyard that Maria entered to empty the vacuum. That was when the dog growled at her and "proceeded to viciously attack" her.

Hearing her screaming, Patricia ran out "where she found her sister covered in blood while she was screaming and crying for help."

Brown immediately called 911, the court documents said, reports aceshowbiz.com.

Patricia claimed that Maria was attacked on her face around her eye and was also bitten on her leg. She "thought her sister was going to die from the blood loss", and has claimed that several inches of skin are missing from Maria's arm. The lawsuit mentioned that Maria needed to undergo two surgeries and stay in the hospital for multiple days.

The incident allegedly caused Patricia to suffer "severe emotional distress" including post traumatic stress disorder (PTSD), severe anxiety, depression and panic attacks.

Through the lawsuit, she's seeking an unspecified amount of monetary damages related to the incident.