In a move aimed at tamping down a mounting controversy over secret money in presidential politics, a political committee backing Mitt Romney Saturday publicly identified a former Bain Capital managing director as the source of a mysterious $1 million contribution to its coffers.

Restore Our Future, the pro-Romney committee, said that Edward W. Conard, who was for years associated with Bain Capital, the huge investment firm that Romney once headed, was the figure behind an obscure company called “W Spann LLC” that was listed as donating $1 million to the group last spring. Conard has continued to list his affiliation with Bain Capital when making sizeable campaign contributions in recent years even though a Bain Capital spokesman said he retired from the firm in 2007.

The disclosure of Conard’s identity, first reported by Politico, would appear to solve a Washington mystery that has swirled for days after NBC News reported this week on the murky origins of W Spann LLC : The company was formed in Delaware in March, made its contribution in April, and then dissolved in July, leaving no paper trail as to who its owners were — or even where it was located.

Full story: Mystery million-dollar Romney donor revealed