PHILIP ELLIOTT, Associated Press

WASHINGTON (AP) — Kansas has seen the greatest number of political ads for state-level offices this election season from groups that do not disclose their donors. In fact, secretive groups account for more than half of the spending in that state’s competitive race for governor, and voters likely will never know who is picking up the tab.

Kansas, however, is hardly alone.

More than $9 million in ads have come from such secretive groups in races for governor and state legislatures in 16 states. That’s according to an analysis released Thursday by the non-partisan Center for Public Integrity.

And the bulk of the spending for next month’s elections is yet to come.