Polygamist Tom Green, the man with five wives, 31 children and two more on the way, is set to be charged with the child rape of one of his wives.
Green, 53, a Mormon fundamentalist from Utah, was jailed for five years last August after being convicted of bigamy and failure to pay child support.
Prosecutors delayed going ahead with the rape charge - which relates to one of Green's wives who became pregnant at the age of 13 - until after his bigamy trial.
He faces life in jail if convicted of sex with a minor.
Green's lawyers had asked the judge to dismiss the charge because the statute of limitations for child rape expires five years after the crime is reported. He married Linda Kunz, now aged 29, in 1986.
State court Judge Guy Burningham ruled that the statute of limitations had not expired because authorities began investigating the alleged crime in 1999.
Ms Kunz is now pregnant to Green for a second time.
The decision came a month before the start of the Winter Olympics in Utah's Salt Lake City.
The court case will once again put the spotlight on plural marriages, that once thrived among Mormon pioneers who settled in Utah, just as the world is watching.
"It's a big setback," Green's lawyer John Bucher said.
Some of Green's wives and children testified that officials long knew of the marriage, though dozens of law enforcement officers testified at a preliminary hearing that they didn't remember any such reports before 1999.
Prosecutor David Leavitt said he intended to pursue the case involving Ms Kunz, even though she was still married to the avowed polygamist.
Green was tried and found guilty in May for living with five wives at the same time and fraudulently collecting $150,000 in welfare.
The case was believed to be the first brought against a polygamist in the US in nearly 50 years.