A 12-year-old girl who had an abortion last month after being raped has sued the state of Mississippi for refusing to pay for the procedure.

The unidentified girl and her mother claim that the state is breaking a US federal law that requires the payment of health insurance under the public Medicaid scheme for poor women whose pregnancies were victims of rape or incest.

Medicaid helps fund treatment for needy, elderly, and disabled people, and for low-income families with children. Individual states determine eligibility, and Mississippi allows coverage for abortions only when the mother's life is in danger.

The girl became pregnant after being raped by a 24-year-old man, according to the lawsuit filed this week in the US district court in Jackson.

"The child was in shock," said David Ingebretsen, head of the Mississippi American Civil Liberties Union, which is representing her, her mother, and the abortion clinic. "She was suffering from health problems due to the pregnancy and the act itself and [was] terrified at the thought of having to raise a baby at the age of 12."

He called Mississippi's policy "inhumane as well as unconstitutional".

But state senator Alan Nunnelee said: "When we involve using taxpayers' money to pay for abortions, we should be very limited in what we do."

AP, Jackson, Mississippi