California's Fair Political Practices Commission plans to investigate the Mormon Church's spending in the campaign against same-sex marriage in the state, the Salt Lake Tribune reports.

Mormons were key to the passage of Prop. 8, which overturned a California State Supreme Court decision legalizing same-sex marriage. The Tribune says Mormons "are believed to have contributed as much as $22 million to the cause."

But one group, Californians Against Hate, believes that the Mormon Church may not have reported all of the money it spent. The Tribune says that Fred Karger, who heads the group, "alleged in his complaint that The Church of Jesus Christ of Latter-day Saints failed to report money invested to organize phone banks, send out direct mailers, provide transportation to California, mobilize a speakers bureau, send out satellite simulcasts and develop Web sites as well as numerous commercials and video broadcasts."

The church itself hasn't commented on the news, but has said before that Karger's complaint contains "many errors and misstatements."