A violent New York man has reportedly butchered his lover and her unicorn-loving daughter aged six who watched her mum die before she was murdered herself.

The incident took place in an apartment on Monticello Avenue in The Bronx in New York City over the weekend.

The dead bodies of Gabrielle Muniz, 26, and her six-year-old daughter Rozara Estevez were discovered with multiple stab wounds at around 11.50pm on Saturday.

The mother reportedly suffered numerous stab wounds to her head, arms and back while the girl sustained multiple knife wounds to her face as well as a blunt-force trauma to her head.

Caleb Duberry, 34, who was on parole for assault at the time of the double murder, allegedly committed the crime before taking his own life.

According to reports, he fatally stabbed himself at around 12.15pm the following day as cops closed in after barricading himself in a flat about a mile from the murder scene.

Muniz’s mother Yanik Rocha said her daughter had been dating the suspect, but that he was not the girl’s father.

Muniz’s sister Gisselle Muniz, who lives in Florida, said: “I’m disgusted at what happened because it not only took my sister but my niece.

“She loved her unicorns. She was so sweet. Just thinking about her and hearing her voice in my head, I can’t believe that this happened to her, too. She was so sweet and innocent. She just turned six.”

She added: “I’m sure she watched her mummy die before she was taken.”

She said she added the suspect to the lease several months ago and that they had been together for less than a year.

Gisselle also said that her sister worked for a law firm and was studying pharmacy in her spare time, adding: “She was doing so well. I never expected this to happen. She did so much for her daughter. That was her main motivation.”

The deceased suspect had previously been arrested numerous times for robbery, assault, and gun possession, according to local media.

A motive for the double murder is currently unclear as the investigation continues.