The girlfriend attacked her partner with a kitchen knife (file photograph)

An enraged girlfriend hacked off her boyfriend's penis with a kitchen knife after forcing him to have sex with her one last time when he refused to marry her.

The grisly incident occurred at 11.30am on Wednesday in front of the couple's family, who were in the house at the time.

The 23-year-old girlfriend had brought up the dicey topic of marriage only for the 35-year-old street vendor called Ravi to say they weren't going to have a wedding day.

She then forced him into the bathroom, demanded he have sex with her, and then chopped off his genitals.

Ravi was rushed to the Sanjay Gandhi Memorial hospital for emergency surgery after he was attacked in outer Delhi in the Mangolpuri area.

The couple had been together for four years before she maimed him, and now the girlfriend is on the run.

The bridge that leads into the outer Delhi area of Mangolpuri, where the incident happened

Her brother and sister-in-law were in the house at the time and witnessed him being stripped and shoved into the bathroom, according to the Times of India.

The 23-year-old had told him there would be 'dire circumstances' if he did not do as she said, but after having sex with him, she still attacked him.

The injured Ravi sprinted from the house screaming for help when neighbours spotted him and called the police who are still hunting for the girlfriend.