MADISON, Wis. — The conservative group at the center of the investigation into Gov. Scott Walker's 2012 recall campaign accused the state's election board in a complaint unsealed Friday of improperly plowing ahead with its probe.

The Wisconsin Club for Growth alleges in the complaint that top officials of the Government Accountability Board launched the John Doe investigation without first getting approval from its six-member board, then continued the investigation even after the board voted to end GAB involvement in July, the Wisconsin State Journal (http://bit.ly/1sQp8Ln) reported Friday.

The group sued the government ethics watchdog in Waukesha County Circuity Court in May, arguing the board overstretched its authority by "by pursuing and funding a far-reaching criminal investigation into virtually every conservative-leaning group in Wisconsin." Judge Lee Dreyfus Jr. unsealed much of the Club for Growth's complaint Friday at the group's request.

The group's complaint alleges board chief counsel Kevin Kennedy and Jonathan Becker, administrator of the agency's Ethics and Accountability Division, waited two months to inform the board about the investigation. It also alleges that the board has examined "hundreds of thousands of documents" and hired four investigators to conduct the probe.

A board spokesman referred the newspaper's request for comment to an attorney, who did not return a request for comment.

David Deininger, who chaired the board when the John Doe investigation started, defended the board and its staff.

He didn't recall exactly when the board was made aware of the probe, but said an investigation like that "would have been brought to our attention at the earliest opening."

"They would know this would have been something the board needed to be up to speed on from the get-go," Deininger said.

The Wisconsin Club for Growth is an independent group that has spent $11.7 million to influence elections in the state for conservatives since 2007, according to the Wisconsin Democracy Campaign, which tracks spending.

The group is one of several organizations challenging an investigation into whether Walker illegally coordinated fundraising with conservative groups in 2011 and 2012. The probe began in secret, but details have filtered out through court documents.