Texas Rangers are investigating 20 cases of sexual assault and about 50 bigamy charges involving members of the FLDS Church, the Deseret News has learned.

Texas officials on Monday confirmed the number of open cases but would not say how many suspects were involved.

"We are working with several other agencies on this investigation, and I do not know what ultimately the team will decide to do as far as possible charges filed," Texas Department of Public Safety spokeswoman Tela Mange said.

The investigation has already prompted five indictments, including one against the church's leader, Warren Jeffs. A Schleicher County grand jury will convene again next week and may consider further indictments.

Rod Parker, a Salt Lake attorney acting as spokesman for the Fundamentalist LDS Church, was surprised by the sheer number of sexual assault and bigamy cases.

And he insists there aren't enough men practicing plural marriage at the Yearning For Zion ranch outside Eldorado, Texas, to come up with 50 bigamy investigations.

"I think they would have a problem coming up with 50 bigamy charges without charging the women," Parker said.

Mange would not go into specifics on suspects.

Even so, Parker believes Texas authorities will have a rough go at convicting a bigamy charge.

Parker said traditionally a person is charged with bigamy because there is deception involved, like a man marrying another woman without that woman knowing he has another wife back home.

"This is completely different. Here we are talking about people who are consenting and know what they are doing," Parker told the Deseret News. "It's hard to see where the crime is."

Last month, Jeffs and four of his followers were indicted by a Schleicher County grand jury on sexual assault charges. One of the men was also charged with bigamy, a first-degree felony.

Jeffs is accused of sexually assaulting a girl younger than 17 in January 2005. Jeffs is currently in a Kingman, Ariz., jail awaiting trial on charges of sexual misconduct as an accomplice, accused of performing underage marriages.

A sixth man was indicted on three counts of misdemeanor failure to report child abuse.

The Texas Attorney General's Office declined comment on any potential charges against members of the FLDS Church.

"The Office of the Attorney General continues to work with local and state investigators; however, we cannot and will not comment on matters related to an ongoing criminal investigation," spokesman Jerry Strickland wrote in an e-mail to the Deseret News.

Parker said he is unsure whether the grand jury will consider new indictments of members of the FLDS Church.