Horrifying CCTV footage shows step-dad drowning his three-year-old girl. He'll be jailed 100 years.

Warning: The footage may be distressing for some viewers.

A man has been sentenced to 100 years in jail after drowning his three-year-old step-daughter by repeatedly throwing her into pool at a Mexican hotel.

A CCTV camera captured the man, who has been identified only as Jose David N., tossing the girl into the water multiple times and watching as she struggles to keep herself afloat.

It’s clear the child is unable to swim, but her step-father just stands idly on the edge of the pool.

He is also seen at one point holding the girl under water.

Other bathers did not come to her rescue.

The incident occurred in the city of Morelia in Mexico in August last year, according to 7 News.

The girl’s mother was reportedly asleep in the family’s hotel room at the time.

Despite being a nurse she said she did not realise her daughter was dead straight away. She then took her to hospital the moment she realised she wasn't breathing.

The Daily Mail reports she only became aware of the extent of her husband's abuse when the surveillance footage was shown in court.

The surveillance footage sparked outrage after it was made public.

Jose remained silent throughout his trial, even as prosecutors recommended he receive a 40 year sentence for the crime.

Judge Garcia Cardona chose a harsher sentence after viewing the footage.

Jose has been given a 100-year sentence without parole.