Lead plaintiff Amy Hagstrom-Miller, president and CEO of Whole Woman's Health, looks skyward as she arrives to speak outside the US Supreme Court after the high court handed a victory to abortion rights advocates, striking down a Texas law imposing strict regulations on abortion doctors and facilities in on June 27, 2016. Reuters/Kevin Lamarque Oklahoma's highest court on Tuesday struck down a law imposing restrictions on abortion providers, including a requirement that they take samples of fetal tissue from patients younger than 14 and preserve them for state investigators.

The law also set new criminal penalties for providers found to have violated abortion-related statutes as well as for anyone found to have helped a minor evade the requirement to obtain parental consent. In addition, the bill created a new, stricter inspection and licensing system for abortion clinics.

Legislators had said the fetal tissue section was aimed at capturing child rapists and that the law would protect women's health. But the New York-based Center for Reproductive Rights, which challenged the law in court, said it unfairly targeted doctors and facilities that perform abortions.

In a unanimous opinion, the nine-member Oklahoma Supreme Court found the law violated the state constitution's requirement that each legislative bill must address only "one subject." The rule, the court said, is designed to prevent legislators from including provisions that would not normally pass in otherwise popular bills.

The state unsuccessfully asserted that each part of the law addressed a single subject: women's reproductive health.

"We reject defendants' arguments and find this legislation violates the single subject rule as each of these sections is so unrelated and misleading that a legislator voting on this matter could have been left with an unpalatable all-or-nothing choice," Justice Joseph Watt wrote for the court.

In a concurring opinion, four of the judges said they also would have struck down the law as an unconstitutional burden on a woman's right to have an abortion.

The state attorney general's office, which defended the law in court, did not immediately respond to a request for comment.

Center for Reproductive Rights President Nancy Northup said in a statement: "This law was nothing but a cynical attack on women's health and rights by unjustly targeting their trusted health care providers."

The law was passed in 2015, but the court had put it on hold while it considered the challenge.

Oklahoma's Republican-dominated government has been at the forefront of socially conservative states that have enacted abortion restrictions in recent years, most of which have been challenged in court.

In June, the US Supreme Court struck down a Texas law imposing strict regulations on doctors and facilities that perform abortions. A similar law is on hold in Oklahoma while the state Supreme Court considers its legality.

(Reporting by Joseph Ax; Editing by Lisa Von Ahn)