The body parts of dismembered children were allegedly found in chicken boxes on Halloween after a 'nervous man' dropped them in front of police.
Police claim they saw the man dropping the packages in Mexico City and proceeded to help him pick up his belongings.
They claim they were then alarmed by the "very white meat" inside the bags, reports El Universal.
The officers began questioning if the man, known only as Edgar Z, 39, if he was OK - to which he replied "Yes I'm fine, I'm fine".
However, the officers were set to be alarmed by the way he desperately tried to gather the dropped 'belongings'.
One agent said: "The person wanted to put the bags back in very quickly, but they were heavy."
An agent said one bag ripped and he was shocked at what he could see inside during the horrific incident on October 31.
He added the "white meat" appeared to be that of a human "arm, shoulder and an ear".
Emergency services were called to the scene.
The man who dropped the chicken boxes claimed he was unaware of the contents of the bag and had been paid to dispose of them by a third party.
It comes after two boys, Alan Yahir “S”, 12, and Héctor Efraín “T”,14, were reported missing in October.
But so far there has been no official link between the grim discovery of the body parts found and the missing children.