US Police have arrested a man for allegedly beheading his one-year-old son with a knife in Northern California, officials said on Monday.

Described by New York Post as 'demonic', 28-year-old Andrey Demskiy attacked his wife and mother-in-law.

Sharing details about the incident, Sacramento County Sheriff’s Office wrote on X: "At approximately 4:15 this morning (Friday), Sacramento County Sheriff’s North Patrol Deputies responded to a residence on the 7500 block of Versailles Way in North Sacramento County for a family disturbance."

"Deputies arrived a short time later and contacted a female outside of the residence, who stated that her husband, 28-year-old Andrey Demskiy, had assaulted her and her mother," the X post said.

Sacramento County Sheriff’s Office said the 'mother' was transported to the hospital by ambulance for her injuries which were non life-threatening.

The police tried to make contact with Andrey Demskiy after arriving at the door of his residence.

The 28-year-old, however, refused to respond or 'surrender peacefully'.

Fearing for the child’s safety, Deputies forced entry into the residence and attempted to detain Demskiy who reportedly remained uncooperative.

"As Deputies took him into custody, they made the gruesome discovery of a severed child’s head in the bedroom where Demskiy was contacted and detained," Sacramento County Sheriff’s Office said in the statement.

"Based on their investigation, Detectives determined that Demskiy was initially involved in a domestic violence incident with his wife and mother-in-law when they both exited the residence and waited for Deputies," the statement said.

Detectives arrested and booked him into the Sacramento County Main Jail.

He will remain in custody.

"He is ineligible for bail," the statement said.