In bizarre and incorrect testimony a “concerned father” has told politicians that he believes equal marriage could lead to greater HIV transmission in Minnesota.

Minnesota resident Mike Frey made a series of inaccurate claims about the virus on Tuesday to the state’s House Civil Law Committee which then passed the proposed same-sex marriage bill last night.

The measure now advances to the Minnesota Senate floor.

Earlier, Mr Frey said he was a “concerned father” and cited Minnesota’s former sodomy law, which defined sodomy as both anal and oral sex in his argument against equal marriage.

He claimed that heterosexual sex could be safer than gay sex because the vagina has a “barrier of cellular tissue that doesn’t allow the sperm… to penetrate the blood flow”.

“When ejaculation occurs inside of a colon, it’s highly absorbent material, the cells do not have a barrier for the sperm and those enzymes to enter into the blood flow,” Mr Frey said. “When the enzymes enter into the blood flow, and a continued, prolonged environment of that happens, these enzymes in the blood flow, it causes what we know as AIDS.”

According to international HIV/AIDS charity AVERT: “Generally women are at a greater risk of heterosexual transmission of HIV. Biologically women are twice more likely to become infected with HIV through unprotected heterosexual intercourse than men.”

Meanwhile, the US Department of Health and Human Services on Women’s Health states that women are particularly vulnerable to HIV infection because of the surface area of the vagina open to exposure and because of the duration semen can stay in the vagina.

It remains to be seen if Mr Frey is aware of these two important points.

In November 2012, Minnesotan voters avoided a constitutional ban on marriage equality, and pro-equality campaigners have since stepped up efforts to push for equal marriage to be legalised.