The Family First Party has disendorsed its candidate for the federal seat of La Trobe, in Melbourne's outer east.

The party says David Barrow misrepresented himself after signing a secret affidavit denouncing the party's values.

In an affidavit posted online Mr Barrow states that he supports the marriage of any committed partnership and says same-sex couples should have the right to adopt. He also declares abortion is a woman's choice.

Victorian Family First chairman Peter Lake says the party had no choice but to disendorse Mr Barrow.

"It came to our attention that he had posted some information on his website and blogs which was inconsistent with the stated position that he had given us as a candidate when we had endorsed him and the views were different to the values that Family First espouses," Mr Lake said.

He says Mr Barrow deliberately mislead the party.

"On his website he has made clear that he had an affidavit signing what his real values were and that that was something he hadn't disclosed to us and he has since posted that on his website and that's inconsistent with the values of the party," he said.

The ABC has tried to contact Mr Barrow.