MADISON, Wis. -

A federal judge has given prosecutors, a conservative group and two unnamed parties more time to review what documents could be unsealed in a secret investigation into whether Gov. Scott Walker's campaign and right-leaning organizations violated campaign finance law.

U.S. District Judge Rudolph Randa halted the investigation in May as part of a lawsuit the conservative group Wisconsin Club for Growth filed challenging investigators' basis for the probe. On June 19 he gave all the parties two weeks to determine what records in the case should remain secret.

That made Wednesday the deadline for the parties' report. On Tuesday the parties filed a joint motion asking to extend the deadline to July 17. They say they have to review more than 3,000 pages.

Randa granted the motion late Wednesday afternoon.