A Hollywood star who won an Oscar for his portayal of a gay man has hit out at opponents of same-sex marriage.
Tom Hanks focused his comments on the Mormon church.
They backed Proposition 8, a ballot measure that passed in California in November, bringing to an end nearly six months of legal gay marriages in the state.
A range of groups are challenging the validity of Prop 8.
“The truth is that a lot of Mormons gave a lot of money to the church to make Prop 8 happen,” said Mr Hanks, one of America’s biggest box office stars.
“There are a lot of people who feel that is un-American and I am one of them.
“I do not like to see any discrimination codified on any piece of paper in any of the 50 states in America.
“A little bit of light can be shed and people can see who’s responsible and that can motivate the next go around of our self correcting constitution and hopefully we can move forward instead of backwards.
“So let’s have faith in not only the American, but Californian constitutional process.”
Dozens of amicus curiae or “friend of the court” briefs have been filed with the state Supreme Court arguing that Proposition 8 drastically alters the equal protection guarantee in California’s Constitution, and that the rights of a minority cannot be eliminated by a simple majority vote. Oral arguments are expected to be heard in March.
Brad Pitt and Stephen Speilberg were among Hollywood stars who donated to the campaign to defeat Prop 8.
Mr Hanks won an Oscar in 1993 for Philadelphia. He plays a gay lawyer who discovers he has AIDS, is fired and then sues his employer for discrimination.