Monica Figueroa confessed to stabbing her four-year-old son to death (Pictures: Henderson County Sheriff’s Office/Newsflash)

A mother allegedly stabbed dead her four-year-old son as the boy’s grandmother looked on.

Monica Figueroa confessed to murdering her son Grayson Hurt and was arrested on Monday, according to Henderson County Sheriff Botie Hillhouse.

Figueroa’s mother, Mary Johnson, called police around 6.40am saying she was afraid her daughter had hurt her grandson.

Police officers responding to the home on the 300 block of Mitchell Street in Athens, Texas, discovered Hurt partly covered by a blanket and dead.