A second convicted child molester has died after being beaten with a walking cane by another inmate at a California prison last week, authorities said Wednesday.

Graham De Luis-Conti, 62, — who was serving a life sentence for aggravated sexual assault of a child under 14 years old — was pronounced dead Sunday, corrections officials said in a statement.

His death came three days after Jonathan Watson, 41, allegedly used the cane to wallop him and another perv in the head at the California Substance Abuse Treatment Facility and State Prison in Corcoran.

The other inmate, David Bobb, 48, — who had also been serving a life sentence for the same charge  — died en route to the hospital Thursday.

Watson has served 10 years of a life sentence for first-degree murder and discharging a firearm, causing great bodily injury or death.

An investigation into the prison beatdown is ongoing.

With Post wires