Former New York Governor Andrew Cuomo’s mayoral campaign improperly coordinated with an outside super PAC on a six-figure ad campaign, New York City’s Campaign Finance Board said Monday.

The New York City Campaign Finance Board withheld the funds after concluding that former Gov. Andrew M. Cuomo likely coordinated ad language with a super PAC.

Former Gov. Andrew Cuomo may have to forfeit more than $600,000 in public matching funds, the New York City Campaign Finance Board announced Monday, stating it had found reason to believe his mayoral campaign had inappropriately coordinated with an independent expenditure committee that’s spending millions of dollars to boost his campaign.