Johnson, who was babysitting Sawyer while her mother was at work, claimed the baby fell and hurt herself

She was placed on life support but never regained

Cody Johnson. 30, has been charged with murder and child sex abuse

An Oklahoma man has been charged with sexually abusing and murdering his girlfriend's baby daughter while he was babysitting her.

Sixteen-month-old Sawyer Paige Jefferson was rushed to hospital on Saturday, unconscious and suffering from severe bleeding and extensive injuries caused by 30-year-old Cody Johnson, according to investigators in Tulsa.

The toddler was placed on life support but did not regain consciousness and died a short time later.

Johnson’s arrest report states that he was babysitting Sawyer on Saturday when he called the girl’s mother at work asking her to come home at once because her child had been hurt.

The woman found Sawyer bleeding and took her to St Francis Hospital’s emergency room.

Upon arrival, the little girl was unresponsive and in cardiac arrest.

Doctors at the ICU made note that Sawyer had numerous contusions on her face, as well as bruising and bleeding from her body, states the report cited by Tulsa World.

The extent of the girl's internal trauma was described in the arrest documents as consistent with 'extensive forcible penetration'.

Sawyer Jefferson died Saturday at St Francis Hospital in Tulsa (pictured) after being taken there by her mother

When asked about what happened to the toddler, police say Johnson claimed Sawyer slipped on her pajamas and fell on a toy while he was looking after her at the condo her shared with her mother.

He was initially booked on charges of child abuse and child sexual abuse. After the girl's death, police added a first-degree murder charge.

Corporal Greg Smith, of the Tulsa Police Department, called it one of the worst child abuse cases he has ever encountered, reported the station NewsOn6.

Johnson’s criminal record includes previous convictions for knowingly concealing or receiving stolen property and driving under the influence.