A $6 million lawsuit filed against the Oregon Department of Human Services accuses child welfare workers of failing to intervene after a 7-year-old girl reported that her grandfather was sexually abusing her.

Over the next two years, the girl’s paternal grandfather repeatedly molested her, according to the suit. The abuse stopped only when the girl told police, the suit says.

Her grandfather ultimately was sentenced to 10 years in prison.

The lawsuit, filed Monday in Multnomah County Circuit Court, is the latest in a string of litigation over the years accusing the child protective agency of failing to shield children from abusers despite clear warnings that the children were in danger.

Agency spokeswoman Christine Stone declined comment, citing the pending lawsuit.

According to the suit, the girl told her therapist in May 2011 that her grandfather would lay on top of her in bed and move his hips back and forth over her. The therapist immediately called the Department of Human Services' child abuse hotline.

The suit says the girl's father didn't believe the grandfather was abusing the girl but agreed not to let the grandfather see her anymore. Child protection officials didn't investigate further or take any action, the suit says.

But the girl did see her grandfather again and again and sometimes slept over at his Vancouver house.

The girl, who was from Oregon, was living with her father when the abuse started and with her mother in 2012, shortly after the department closed the case.

The abuse continued until August 2013, when the girl, then 9, told Vancouver police that her grandfather was molesting her.

The suit faults the Department of Human Services for allegedly failing to act on the girl’s initial report of abuse. It also faults the agency for allowing the girl to live with her father, despite his trips in and out of jail and his failure to attend a parenting class, according to the suit.

The father's criminal history includes convictions for cocaine possession and raping a minor, and he was required to register as a sex offender, the suit says.

The girl is now 14.

Portland attorneys John Devlin and Josh Lamborn filed the lawsuit on behalf of the girl.

-- Aimee Green