MADISON, Wis. — A request by Wisconsin’s education department for information about students with disabilities attending private voucher schools sparked an angry response from conservatives this week, not unlike what happened in Louisiana in reaction to a voucher investigation there.

In Wisconsin, the state Department of Public Instruction last week asked for taxpayer-subsidized voucher schools to voluntarily turn over the information as part of a U.S. Justice Department investigation. It is looking into alleged discrimination in the program against students who have disabilities.

Students with disabilities are typically more expensive to educate, but voucher schools receive the same taxpayer subsidy for every student. Repeated attempts to have higher vouchers for students with disabilities have failed in the Legislature in recent years.

In Louisiana, the Justice Department tried to block the state from issuing future vouchers in districts under civil rights-era desegregation orders unless the state first obtained federal court permission. Republican Gov. Bobby Jindal tried to use it against Democrats by accusing President Barack Obama of trying to deny school choice to poor children.

Wisconsin Republicans are taking a similar approach, accusing the Justice Department of working with the state Department of Public Instruction to intimidate voucher schools and undermine the program.

“If Eric Holder wants to go fishing in Wisconsin, we have more than 15,000 lakes, we will gladly find him a boat and a guide,” said Sen. Alberta Darling, R-River Hills, and Rep. John Nygren, R-Marinette, co-chairs of the Legislature’s powerful budget committee in a joint statement.

John Johnson, spokesman for the state education department, stressed that the information request was voluntary.

“We are interested in the education of all children,” Johnson said in a statement Tuesday. “In this particular situation, the education of children with disabilities is vitally important and we must ensure there are not any discriminatory practices occurring to the best of our ability.”

If there are no problems with the program, its supporters should not fear releasing the requested data, said ACLU attorney Courtney Bowie.

“They want absolutely no federal oversight, no interference from the federal government at all,” she said. “If the program is designed to exclude certain students, groups of students, then we’re on a slippery slope.”

The voucher program began in 1990 in Milwaukee, which became the nation’s first city to offer the taxpayer subsidies to help poor children escape struggling schools. Since 2011, Republican Gov. Scott Walker and the GOP-controlled Legislature have expanded it statewide, eliminated enrollment caps in Milwaukee and Racine, and raised income limits to allow middle-class students to participate.

Walker’s spokeswoman Laurel Patrick declined to answer a question about the DPI request, instead saying the governor is “focused on improving education options for all students.”

The Justice Department investigation is in response to a complaint filed in 2011 by the American Civil Liberties Union and Disability Rights Wisconsin. The groups said disabled students are deterred from participating in the program, denied admission when they do apply, and expelled or forced to leave as a result of policies that don’t accommodate their needs.

The Justice Department has said it would evaluate progress made toward eliminating any discrimination and identify what further steps may be needed to ensure compliance at the end of the 2014 school year.

More than 27,000 students use vouchers in Wisconsin, with all but about 2,000 of them in Milwaukee. To qualify, a family of four can earn up to nearly $72,000 in Milwaukee and Racine and up to about $44,000 in the statewide program.

Private schools in the voucher program can’t be required under current state law to make available information about students with disabilities, while public schools are required to do so. Rick Esenberg, an attorney and president of the conservative Wisconsin Institute for Law and Liberty, said he thinks that even asking for the information to be turned over voluntarily could be a violation of the law.

Esenberg further cautioned that schools could run afoul of student privacy laws by turning over requested information such as the student’s disability, and advised that they consult with attorneys before doing anything.

A spokesman for the DPI was checking Wednesday to see if any schools had submitted the requested information and did not immediately have a tally. School Choice Wisconsin, an advocacy group for the voucher program, is advising its members not to turn over the records, said its president Jim Bender.

While the conflict continues in Wisconsin, in Louisiana a federal judge ordered the state to provide federal officials with a variety of reports, including lists and information on voucher applicants and periodic reports on enrollment and racial breakdowns at state public schools. Both Jindal and Holder said they were pleased with the ruling but some voucher supporters are fighting it as a needless federal intrusion.