CHICAGO — Texas prosecutors Wednesday moved to seize the ranch of a polygamist sect where more than 450 children were earlier removed in a police raid and its leaders jailed on child sex abuse charges.

Prosecutors described their motion to seize the sprawling 1,600 acre ranch as the "final chapter of the state's nearly five-year effort to pursue widespread criminal misconduct at the YFZ Ranch."

They argued that sect leaders aimed to "establish a remote outpost where they could insulate themselves from criminal prosecution for sexually assaulting children."

An audit of the church accounts also found that the 2003 purchase of the West Texas ranch and the construction of a massive compound there were financed with the proceeds of illegal money laundering, prosecutors argued in a 91-page affidavit.

The ranch was also used to illegally harbor sect leader and self-proclaimed prophet Warren Jeffs when he was a fugitive on the FBI's Top 10 Most Wanted List.

Jeffs, 53, was sentenced to life in prison last year for his "spiritual marriage" to two young girls.

His reclusive sect was thrust into the spotlight in 2008 when Texas police seized 468 young boys and girls amid allegations of systemic sexual and physical abuse at the sprawling compound near the small town of Eldorado.

The children were soon returned to their parents when a court ruled that child welfare officials had overstepped their authority.

However, the evidence gathered during the raid was damning.

Documents recovered showed that Jeffs had taken 78 illegal wives -- 24 of whom were underage. He even took two 12-year-old brides in a single day.

He was also shown to be a party to 550 bigamous marriages, of which 67 included people under the legal age.

Jeffs was the eighth man to be convicted of sexual assault, bigamy and other crimes through evidence found in the raid on the Yearning for Zion Ranch. The other convicts' sentences have ranged from six to 75 years in prison.

The Fundamentalist Church of Jesus Christ of Latter Day Saints is said to have about 10,000 members.