San Francisco based Train have expressed their outrage after their single Marry Me was used to promote an anti-gay marriage website launched in New Zealand.
Family First featured the pop song on the Protect Marriage website it launched to oppose a new law which would which would allow all New Zealanders to marry regardless of their sexual orientation.
The band members said it was "upsetting" their song had been used to promote an agenda they do not agree with.
"We (Train) take the idea of marriage very seriously, and believe it is the right of all consenting adults, regardless of sexual orientation.
"'Marry Me' is about just that, finding that special love and making it last forever. Everyone should be allowed to have that," said the band in a statement.
Earlier this week, Twitter users alerted the band to video, asking why they were allowing one of their songs on the site.
A member of the band responded they did not know it was on there and were getting it off as soon as possible.
The Marriage Amendment Act - which would allow gay couples to marry - was plucked from a ballot of more than 60 last week.
Family First NZ opposes the law, saying marriage should come under the traditional religious definition.
The Protect Marriage website has the slogan "one man, one woman, that's marriage".
People can sign a petition against the legalisation of same sex marriages on the site.
The website was temporarily shut down on Monday when it experienced "a large scale denial of service attack".