The pro-Romney super PAC Restore Our Future raised a record-breaking $20 million in June, a fact first reported by the Washington Post, which Brittany Gross, a spokeswoman for the group, confirmed to ABC News.
The haul is four times what the super PAC raised in May, when it brought in $4.9 million. It has raised $80 million in support of Romney so far.
The pro-Obama super PAC Priorities USA also had its best month, raising $6 million, co-founder and former White House press secretary Bill Burton told Bloomberg over the weekend.
The Romney campaign raised more than the Obama campaign in both May and June. Last month it brought in $106 million to Obama's $71 million.
Billionaire casino mogul Sheldon Adelson donated at least $10 million to Restore Our Future, but it's not clear whether this sum is included in the current haul.