Colorado state Rep. Kerry Tipper is crafting a bill to make it illegal for a doctor to non-consensually inseminate a patient with his own sperm.

The Denver Post reports that Tipper’s proposal comes after a Grand Junction doctor, Paul B. Jones, stands accused in a lawsuit of substituting his own sperm for that of an anonymous donor.

“For criminal liability, where in this statue does it belong?” Tipper, D-Lakewood, told The Post. “Is it fraud? Is it a sex crime? Something entirely different? All this matters for a lot of reasons.”

Only three states have fertility fraud statutes, and each treats the crime differently. 

Last month, the Texas Medical Board opened an investigation into a 1986 incident involving a doctor using his own sperm on a patient without her knowledge. The board’s staff originally rejected the complaint, citing a state law that prohibited the board from reviewing cases over seven years old. Board members overruled the decision.

Texas defines insemination without disclosing the source as sexual assault, and makes implantation without consent a felony.

Current cases have been unearthed through DNA testing, with more likely to come forward. A federal insemination report in 1988 disclosed that “few practitioners reported having used their own semen (2 percent).”

“At no time was it appropriate for a physician to use their own semen to inseminate a patient,” said Sean Tipton of the American Society of Reproductive Medicine to the Pew Charitable Trusts. “At no time was it appropriate for a physician to deceive a patient about whose semen they were using.”