The claims refer to law HF 146, also known as the “Trans Refuge bill”.

Mr Walz, Kamala Harris’s running mate in the upcoming US election, signed the bill in April 2023 as part of Minnesota's push to be seen as a “sanctuary state” for transgender individuals. 

“Tim Walz signed a bill that lets the State take away ur kids if you don’t agree to sterilize them & chop off their body parts in the name of ‘gender affirming care’,” one Facebook post reads. 

“So if your 14-yr-old is sad but thinks it’s gender confusion & you object to castrating him, the state takes custody.”

Another post claims the bill allows the “state take away your kids if a child wants to ‘change’ genders but you don’t agree to the ‘gender affirming care’”, adding: “This is shocking communistic control where the State is trying to replace the parent.”

Former US president Donald Trump made a similar claim that Mr Walz signed a law “letting the state kidnap children to change their gender” at a rally in Montana (31 minutes 13 seconds). 

His running mate JD Vance repeated this claim in an ABC interview.

Several experts told AAP FactCheck the claims made about the bill are false. 

The bill was a response to 19 US states signing laws to ban or heavily restrict gender-affirming care for children and in some cases to criminalise the access and provision of it.

Its backers say it is intended to protect the rights of people from Minnesota and beyond to receive gender-affirming health care in the state.

In particular, it gives Minnesota courts temporary emergency jurisdiction in cases where a child comes from interstate for gender-affirming care.

Gender-affirming care is defined as social and medical interventions that affirm a transgender or gender-diverse individual’s identity, including puberty blockers, cross-sex hormones, permanent hair removal, voice therapy and surgery. 

Courtney Joslin, a professor at the UC Davis School of Law, said the legislation does not authorise the state to take custody of children.

“HF 146 addresses the very technical question of which states’ courts have jurisdiction (that is, the power to hear) custody cases between parents when the parents live in different states,” Professor Joslin said.

The law is “really just procedural”, she added, essentially determining the state in which a custody action between parents in different states should be filed.

“It does not address in any way when state officials can take custody of a child away from a parent,” Prof Joslin said.

Minnesota University legal expert, Richard Painter, told AAP FactCheck there's no Minnesotan law allowing the state to take away custody from a parent due to the parent not consenting to gender-affirming surgeries or opposing gender-affirming care.

Kathryn Schumaker, a senior lecturer at the United States Studies Centre, also said the law does not give the state the authority to remove a child from parents who oppose gender-affirming care.

"The legislation addresses a very specific scenario in which a custody dispute crosses state lines, and a child’s parents and/or legal guardians disagree about whether their child should have access to gender-affirming care,"  Dr Schumaker said.

"Should such a dispute arise, and the parent who opposes such care resides in a state that is hostile toward trans rights, the Minnesota law would prevent another state from taking action and giving custody to the out-of-state parent who opposes gender-affirming care."

AFP Fact Check and Snopes have also debunked claims about the Minnesotan Trans Refuge bill.