Published: Jul 13, 2011 8:17 PM EDT
Updated: Jul 13, 2011 7:17 PM EDT

SALT LAKE CITY (AP) - The polygamous family featured on cable television's "Sister Wives" is planning to challenge the Utah bigamy law that makes their lifestyle illegal.

Attorney Jonathan Turley is expected to file the lawsuit in Salt Lake City's U.S. District Court on Wednesday.

Turley represents Kody Brown and his four wives - Meri, Janelle, Christine and Robyn.

Formerly, of Lehi, the Browns belong to the Apostolic United Bretheran church, which practices polygamy as part of its faith. The Browns and their 16 kids moved to Nevada in January after Utah authorities launched a bigamy investigation. Bigamy is a felony in Utah.

Turley said the lawsuit doesn't aim to challenge Utah's right to refuse to recognize plural marriage.

"This lawsuit is less of a polygamy challenge than it is a privacy challenge," Turley said.

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