A leading House lawmaker asked Attorney General Eric H. Holder Jr. on Friday to provide an array of documents and data relating to the Justice Department’s role in tens of thousands of cash and property seizures made in recent years by state and local police under federal civil asset forfeiture laws.

The request by Rep. F. James “Jim” Sensenbrenner Jr. (R-Wis.), chairman of the House Judiciary subcommittee on crime, terrorism, homeland security and investigations, is part of an inquiry into the billions of dollars in seizures made through the Justice Department’s Equitable Sharing Program, the federal government’s largest asset forfeiture initiative.

“While we must ensure law enforcement is properly equipped, they should not be funded by slush funds accrued by violating Americans’ civil liberties,” Sensenbrenner said in a statement Friday.

Sensenbrenner asked Holder for details about the policies governing such seizures and the standard of proof necessary before the federal government “adopts” a state or local seizure into the Equitable Sharing Program. Federal civil seizures can occur when police say they believe property is tied to crime through a preponderance of the evidence.

Sensenbrenner said he is concerned that local authorities turn to the Justice Department’s program when state civil asset forfeiture laws are stricter than the federal standards. He said he worries that police have sometimes trampled individual rights when making cash and property seizures without filing criminal charges­.

“The implications on civil liberties are dire,” he said in the letter to Holder. “The right to own property is a fundamental right implicitly recognized in the Fourth, Fifth and Fourteenth Amendments. I also believe that it is a human right.”

Sensenbrenner’s request follows a Washington Post investigation that found that 61,998 cash seizures have been made on U.S. highways and elsewhere since the Sept. 11, 2001, attacks without search warrants or indictments through the Equitable Sharing Program, totaling more than $2.5 billion.

The Homeland Security and Justice departments and other federal agencies received $800 million of that total; state and local authorities kept the rest.

Friday’s letter follows similar requests by Sensenbrenner for documents from the Drug Enforcement Administration and the Immigration and Customs Enforcement. In those letters, Sensenbrenner sought details about how challenges from cash and property owners are handled.

Although owners can seek to get their property back through the federal courts, the cost is often prohibitive. Sensenbrenner noted that there is an administrative process for property owners but that agency decisions are “not subject to subsequent challenge.”

The Post investigation found that only about a sixth of the seizures were legally challenged. But in 41 percent of the challenged cases — more than 4,000 — the government agreed to return all or part of the money. The appeals process often took more than a year and required owners of the cash to sign agreements not to sue police over the seizures.

“Given these inherent conflicts, what procedures and protections exist to ensure fair adjudications of the claims and to protect against conflicts of interest?” Sensenbrenner said in the ICE letter.

He told The Post in a statement that the asset forfeiture system “raises serious Constitutional and ethical red flags. I strongly believe this deserves scrutiny and aggressive Congressional oversight.”