COLUMBIA — A national conservative watchdog group has added a new wrinkle to the contentious debate over South Carolina’s voter ID law.

Judicial Watch announced Tuesday that it has sued the Department of Justice, saying it has not turned over public records related to its decision to block the state’s requirement that voters present government-issued photo IDs in order to vote.

The Justice Department did not respond to a request for comment.

Judicial Watch said it filed a Feb. 6 Freedom of Information Act request for the records, and the Justice Department acknowledged receipt of the request 10 days later.

But the department still has not turned over any records, which were due no later than March 29, the conservative group said Tuesday.

Judicial Watch filed a lawsuit against the department over the matter in U.S. District Court last week.

The group supports voter ID measures and said the Justice Department’s lack of response to the request suggests the Obama administration has something to hide.

The department rejected the Palmetto State’s voter ID law late last year, claiming it discriminated against minority voters.

In response, S.C. Attorney General Alan Wilson sued the Justice Department earlier this year, arguing the law is fair.

A three-judge federal panel will hear the case beginning in late July and could issue a ruling by mid-September.

As they prepare for arguments, the Justice Department has begun to depose lawmakers and others who played prominent roles in the debate and passage of the law last year.

The Post and Courier has confirmed House Speaker Bobby Harrell and Lt. Gov. Glenn McConnell, both Republicans from Charleston, are among those scheduled to provide depositions this week.

Gov. Nikki Haley’s chief of staff, Tim Pearson, also will be deposed this week, though the governor herself is not scheduled to be deposed, her spokesman said.

Charleston GOP Sen. Chip Campsen, who sponsored the voter ID bill, said he is scheduled to be deposed next week.

The S.C. Attorney General’s Office said Tuesday that it had been advised by legal counsel not to provide a full list of who DOJ will depose.

The Justice Department did not respond to a request for information on scheduled depositions.

Reach Stephen Largen at 864-641-8172 and follow him on Twitter @stephenlargen.