HOUSTON -- Autopsy results were completed on a six-month-old baby boy found in a southwest Houston motel freezer, but the cause of the death is still pending, KPRC Local 2 reported Monday.

Crystal Sosa, 25, and Dezmond Dewayne Blake, 28, were arrested after police found the baby's body in a zipped-up duffel bag inside the freezer in a room at the InTown Suites, 3000 state South Highway 6, on Friday.

The child, identified as Devin Blake, had been in the freezer for about a year, officials said.

The medical examiner has not yet been able to determine of the child died of natural causes, as the mother claimed.

According to a probable cause affidavit, Sosa makes her living as a prostitute. The affidavit also states that both Sosa and Blake are heavy drug users.

Sosa told police she came home and had a heated argument with Blake. During that argument, she noticed the baby was not reacting to the noise.

Sosa checked the baby, who was lying in a crib on his back with a bottle in his mouth. Sosa said he was dead.

Sosa said she wanted to call 911, but did not because she said both she and Blake were drug users, one child had already been removed from their custody, and because of her personal history with the police.

She said they wrapped the body in a blanket, put the corpse inside a gym bag, and put the bag in the freezer.

Sosa said she and Blake continued to use the freezer for ice and frozen food items, such as pizza.

Blake and Sosa are charged with felony tampering with evidence. However, the charges could be upgraded.

Bail was set at $50,000 each. Sosa and Blake are due back in court on Tuesday to have an attorney assigned.

The Harris County Medical Examiner's Office completed an autopsy on Sunday, but the cause of death was still pending. The results may be known as early as Tuesday.