MADISON, Wis. -

A coalition of media and open government groups are pressing a federal appeals court to release nearly three dozen documents linked to a secret probe into Gov. Scott Walker's campaign.

Prosecutors have been looking into whether Walker's 2012 recall campaign illegally coordinated with conservative groups. A federal judge halted the probe in May after one of the groups, Wisconsin Club for Growth, argued the investigation violates its free speech rights. The 7th Circuit Court of Appeals is considering re-starting the probe.

The court planned to release 34 documents in the case Tuesday but held off after Wisconsin Club for Growth, two unnamed parties and the prosecutors filed motions seeking to keep all or parts of the documents sealed.

The coalition filed arguments Wednesday contending the need for secrecy is weak.