It has been revealed that Mitt Romney’s political action committee (PAC) made a $10,000 donation in 2008 to the National Organization of Marriage in its fight to repeal the granting of marriage licences for same-sex couples in California through the infamous Proposition 8.

That Mr Romney was opposed to equal marriage, and that he had intended to donate to NOM was never a secret. But, the Human Rights Campaign has uncovered evidence to the effect that the manner in which the donation was advanced has been secretive and unusual. Records lodged by the Mr Romney’s Free and Strong America PAC with the Federal Election Commission failed to include details of the said donation. The same was the case with the public 99o form. HRC obtained these findings through a whistleblower, according to US media reports.

These revelations are particularly sensitive, as the NOM has become embroiled in a controversy for plans to “drive a wedge” between African-Americans and sexual minorities, according to documents revealed on Friday.

It would seem that the donation to NOM was made through the Alabama chapter of the Free and Strong America PAC, which the state records affirm. That said, the 990 form does list the donation as having come from a specific PO box in Belmont, Massachusetts. While many politicians are known to take advantage of the southern state’s lax disclosure laws, why Mr Romney, the leading contender in the race for Republican presidential nomination, had to take the circuitous route to make his donation.

“It’s clear now that Romney was a major financial donor to Prop. 8,” said Fred Sainz, HRC’s vice president for communications. “But it’s also clear that his campaign very cleverly hid this contribution in an obscure Alabama PAC.”

The notorious Californian referendum, which has since been declared unconstitutional, was supported substantially by the Mormon Church, to which Mr Romney belongs, and it is known that his family members gave up to $1,400 in support of the proposition campaign.

NOM, meanwhile, has defended its efforts targeting ethnic minorities. “Gay marriage is not a civil right, and we will continue to point this out in written materials such as those released in Maine,” NOM president Brian Brown said in a statement. “We proudly bring together people of different races, creeds and colors to fight for our most fundamental institution: marriage.”