The heartwarming sight of children from a polygamist sect being returned to their mothers this week is hardly the end of the story of what went on at the Yearning for Zion ranch in Texas. The court-ordered reunification is, on balance, a positive development. But an investigation into claims of sexual abuse at the Zion ranch continues - and that, too, is wholly appropriate.

Texas authorities raided the Eldorado ranch two months ago after receiving an anonymous complaint of abuse and took into custody hundreds of children over the objections of their mothers. There was almost certainly something illegal going on at the ranch run by a fundamentalist offshoot of Mormonism. But given the apparent lack of imminent danger (the key word being imminent), the Texas Department of Family and Protective Services acted somewhat precipitously - particularly in removing the very youngest children, for whom separation from their families was traumatic.

It was a difficult decision - and it doesn't help the authorities' case that the tipster whose phone call triggered the raid has never been found. But Texas authorities cannot be faulted for responding vigorously to a claim of child abuse. And although residents insist there was no abuse at Yearning for Zion, a sect leader's claim that his group will no longer allow underage girls to marry does not inspire confidence about past practices.

It is to be hoped that DNA test results, due to be released soon, will reveal how widespread a problem statutory rape has been at the polygamists' ranch.

Of course, polygamy itself is also a crime, and not necessarily a victimless one.

But let's not lose sight of the main issue here: A man having sex with a child is a serious crime, and questions about religion or culture should not be allowed to muddy that fact.