Republican presidential candidate and former Massachusetts Gov. Mitt Romney, second from left, tours Screen Machine Industries with its owners July 27 in Pataskala, Ohio. (Jay LaPrete/Associated Press)

Republican presidential candidate Mitt Romney on Monday dismissed criticism of a supporter who used a shell corporation to funnel $1 million to a pro-Romney group.

The donor, former Bain Capital executive Edward Conard, came forward to identify himself last week after watchdog groups began calling for federal investigations into the mysterious contribution to the Restore Our Future PAC. Conard had arranged the contribution through a firm called W Spann, which was created in Delaware in March and dissolved in July with no evidence of any business activities other than the donation.

“He came out and discussed who he is, so there’s not much question anymore — no controversy because he said, ‘Hey, it’s me, and I’ve given to Mitt many times before,’ ” Romney said when asked about the controversy at a stop in Concord, N.H.

Later Monday, when Romney faced additional questions from reporters in Manchester, N.H., about the donation, he said he believed that the controversy “disappears” now that the donor has identified himself.

The donation to Restore Our Future underscored the extent to which outside donors are now free to spend money on politics without revealing their identity. A Supreme Court ruling in 2010 allowed corporations to spend unlimited amounts of money on elections, opening the door to contributions such as the one from W Spann.

Romney’s views on the role of money in politics have evolved since the beginning of his political career in Massachusetts, when he suggested banning political action committees and limiting spending and contribution sizes in federal campaigns. In the 2008 campaign, Romney inveighed against “hidden special interests” and criticized the McCain-Feingold campaign-finance law for leaving an “enormous, gaping loophole” allowing independent political groups to spend unlimited funds on elections.

Restore Our Future is a “super PAC” formed by three former Romney aides to support his candidacy. It is unbounded by campaign limits, raising $12 million in the first half of this year. Under federal election rules, the group is barred from coordinating directly with the campaign, but Romney is free to solicit money on its behalf; the candidate spoke at a private fundraising dinner for the group last month.

Although the Supreme Court ruling makes clear that companies are free to donate money to such groups, campaign watchdogs argued that W Spann may have violated federal laws prohibiting the use of a “straw donor” to hide the source of a contribution.

Staff writer Philip Rucker in Concord, N.H., contributed to this report.