SAN ANGELO, Texas (CNN) -- Texas authorities say they collected DNA swabs from jailed polygamist sect leader Warren Jeffs in connection with a criminal investigation involving "spiritual marriages" to four girls ages 12 to 15.
Polygamist sect leader Warren Jeffs is jailed in Arizona awaiting trial on 10 felony counts.
The samples were taken Thursday in Arizona from Jeffs, the sect's jailed 52-year-old "prophet," said Jerry Strickland, spokesman for the Texas attorney general's office.
Jeffs is leader of the Fundamentalist Church of Jesus Christ of Latter-day Saints.
The criminal investigation moved to the forefront Friday as a Texas judge refused to sign an order returning to their homes more than 300 children seized last month from the polygamist sect's ranch. Judge Barbara Walther said she wanted all the mothers involved to sign the order first.
In the criminal investigation, marital records -- known as bishop's records -- were seized April 3 from the sect's Yearning for Zion ranch, according to an affidavit for a search warrant seeking the DNA samples. The records show that Jeffs married a 14-year-old girl January 18, 2004, in Utah, the affidavit says.
Jeffs "married" three other underage brides -- two 12-year-olds and a 14-year-old -- at the sect's 1,700-acre ranch near Eldorado, Texas, the affidavit says.
The court document refers to photos of Jeffs with his alleged child brides. In one picture, the affidavit states, he is kissing one of the 12-year-olds. In another, he is with a 15-year-old wife at the birth of their child in October 2004, according to the affidavit.
Jeffs is believed to have "committed the felony offense of sexual assault of a child," the affidavit says. One of the 12-year-olds, who was believed to have married Jeffs on July 27, 2006, allegedly was sexually assaulted by him that day, the affidavit states.
The DNA samples will allow authorities to determine whether he is the father of the children born to underage mothers, according to the court documents.
Jeffs' Arizona attorney, Mike Piccarreta, was not available for comment Friday, according to his office.
The criminal investigation, led by the Texas attorney general's office, is separate from an ongoing custody dispute involving the sect. A hearing in the custody case is scheduled later Friday in San Angelo. Timeline »
Texas officials began planning Friday how they would return the FLDS children after a court ruling that the removals were unwarranted.
An agreement was being discussed in court Friday afternoon before Judge Barbara Walther. Under a draft of a court order released to the public during the session, the children would be returned starting Monday.
The draft applies to 330 children. It was not immediately known how the state would handle returning another 110 children.
Attorneys for the state and the FLDS families are discussing conditions:
Parents picking up their children would be required to have their photo and the child's photo taken and to sign a release acknowledging they agree to the conditions.
The proposed pact was being struck a day after the Texas Supreme Court ruled that social workers overstepped their authority in rounding up more than 460 children from the YFZ ranch.
Child Protective Services did not present sufficient evidence that children were being abused, the state's highest court ruled, upholding a lower appeals court.
The ruling came in the case of 38 mothers who had appealed the removal of their children, but attorneys have said the reasoning can be applied to all the children taken in the April raid. Watch the sect's spokesman demand the children back »
State officials have said the sect, with its polygamist beliefs, groomed young boys on the ranch to be abusers. FLDS members deny any sexual abuse at the ranch and claim that they are being persecuted because of their religion.
Jeffs is jailed in Mohave County, Arizona, awaiting trial on five counts of sexual conduct with a minor, four counts of incest and one count of conspiracy to commit sexual conduct with a minor.
If convicted, he could face more than three years in prison. In November, he was sentenced to two consecutive terms of five years to life in Utah after being convicted on two charges of being an accomplice to rape in connection with a marriage he performed in 2001.
He was accused of using his religious influence over his followers to coerce a 14-year-old girl into marriage with her 19-year-old cousin. The girl, Elissa Wall, testified that she repeatedly told Jeffs she did not want to be married and that she was uncomfortable with sexual advances from her husband, Allen Steed, who is now awaiting trial on rape charges.
Jeffs' trial last year thrust the FLDS into the national spotlight, and April's raid on the YFZ ranch intensified scrutiny on the sect.
In addition to the YFZ ranch, the FLDS is prevalent in the twin border communities of Hildale, Utah, and Colorado City, Arizona.
The FLDS is not affiliated with the mainstream Mormon church, which renounced polygamy more than a century ago. Critics of the sect say it arranges marriages for girls as young as 13 to older men.
CNN's Tracy Sabo and Gary Tuchman contributed to this report.