An Argentinian prisoner serving time for killing his wife on a conjugal visit has murdered his new girlfriend when she went to visit him in prison.

Gabriel “Chirete” Herrera stabbed his girlfriend Andrea Neri, 20, in front of her two-month-old baby, during a private visit in a prison in Villa de las Rosas, Argentina.

The 39-year-old allegedly emerged from the room holding the baby and confessed to a guard that he had killed Ms Neri.

The baby was unharmed in the incident and is now thought to be in the care of the victim’s mother.

Herrera was arrested in 2003 on robbery and murder charges and strangled his wife Veronica Castro, 29, during a conjugal visit in Metan Prison in 2006.

Herrera allegedly emerged from the room after the incident and told the victim’s mother: “I have just killed your daughter.”

Her mother reportedly attended Villa de las Rosas prison to support Ms Neri’s family.

She told local media: “I told Andrea when she was about to give birth that she should be careful of him because he is a murderer.”

Prisons director Cesar Rodriguez said all prisoners had the right to private visits with their spouse.