A 43-year-old woman and her 23-year-old daughter have been arrested and charged with incest after authorities in Oklahoma discovered they were married.

Patricia Spann, the mother, had lost custody of her three children some years ago. The daughter, Misty, and her two brother were raised by a grandparent.

Ms Spann was reunited with daughter Misty two years ago, and records show that the two women got married in March this year.

The relationship was discovered last month during an investigation by the state’s department of human services into the welfare of children living at the older woman’s house.