The comment aligned Santorum with a lineup of conservative critics bashing Democratic President Barack Obama's rule requiring religious institutions -- but not churches -- to provide health insurance plans that cover birth control.
The rule, announced in January, covers religious-affiliated groups like charities, hospitals and universities. The Catholic Church opposes most methods of birth control and conservatives have painted the rule as an attack on religious freedom from a secular president.
Speaking to CNN's John King, the former Pennsylvania senator said: "That's the Church's money, and forcing them to do something that they think is a grievous moral wrong. How can that be a right of a woman? That has nothing to do with the right of a woman."
Santorum bills himself as the only true conservative in the field of Republicans vying to win their party's nomination to challenge Obama in November. He's backed by evangelical leaders and social conservatives who admire his consistent and at times polemical stances on abortion and gay marriage. He swept nominating contests Minnesota, Missouri and Colorado on Tuesday buoyed by votes from social conservatives.