McALLEN, Texas - A national consumer advocacy group sued the federal government Wednesday on behalf of a University of Texas law professor seeking documents about the planning of the border fence.

U.S. Border Patrol agents block the path of protestor Pedro Rios, right, as he attempts to walk up to the U.S.-Mexico border fence at Border Field State Park in San Diego Saturday, Feb. 21, 2009. (AP Photo/Denis Poroy) Public Citizen, the group founded by Ralph Nader, filed a lawsuit in U.S. district court in Washington against the Department of Homeland Security, Customs and Border Protection and the Army Corps of Engineers.

The suit alleges the agencies didn't comply with a request from the University of Texas Working Group on Human Rights and the Border Wall. Denise Gilman, a law professor and member of the group, used the Freedom of Information Act to request documents in April regarding the location of the fence segments and criteria used in determining its placement.

The lawsuit asks that the government provide the documents.

The government is nearing completion of 670 miles of fencing along the U.S.-Mexico border. The project has met widespread opposition in South Texas, where segments will touch hundreds of private property owners and leave thousands of acres of farmland between the fence and the Rio Grande.

The Texas group has suggested the fence disproportionately impacted low-income minorities.

"Researchers have found statistically significant differences between the income and race of property owners whose land will be affected by the wall versus those whose land will remain unaffected," the lawsuit reads. "Affected property owners are, on average, less wealthy and include more people of color than property owners whose land will not be affected."

According to the lawsuit, the Department of Homeland Security referred Gilman's request to Customs and Border Protection, which is overseeing the fence project.

That agency has provided a partial response to Gilman's request. The Army Corps of Engineers told Gilman that her request would incur copying costs of $54,545 and after appeals partially filled her request.

A Customs and Border Protection spokesman did not immediately return a call for comment.

"We sincerely hope that the Obama administration, which has pledged greater transparency and accountability in government, will release the requested documents so that informed debate and consultation regarding the border wall can take place before there is any further construction." Gilman said in a prepared statement.