California’s political watchdog agency on Thursday announced the largest fine in its history for campaign-reporting violations and ordered two political action committees to pay the state $15 million for failing to properly report the source of funds spent in the 2012 election.

The California Fair Political Practices Commission called the two groups that will pay the $1 million fine “part of the ‘Koch Brothers Network’ of dark money political nonprofit corporations.” The reference is to billionaires Charles and David H. Koch, who have given millions to conservative causes across the country.

The $15 million in payments ordered to the state’s general fund stem from separate unreported out-of-state contributions to two PACs last fall:

●$11 million that the Laguna Niguel-based Small Business Action Committee received from Phoenix-based Americans for Responsible Leadership, which got the money from another Phoenix-based nonprofit, the Koch-backed Center to Protect Patient Rights.

●$4 million that went to the Iowa-based California Future Fund for Free Markets Yes on Proposition 32 from the American Future Fund, which received the money from the Center to Protect Patient Rights.

As part of the settlement, ARL and the CPPR each agreed to pay $500,000.