Andrew Cuomo’s mayoral campaign may have improperly coordinated with an outside super PAC spending heavily on his behalf, according to the city’s campaign finance regulators, who announced Monday that they would withhold $622,000 in public money from the ex-governor’s campaign while they investigated the issue.

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.

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