SALEM, Ore. -- Jail documents say two sons of a Turner couple held on charges of child abuse told detectives that their parents punished them by hitting them with two-by-fours or pieces of iron pipe.

MCSO photos

Graydon and Robyn Drown

Documents filed by Marion County investigators show the sons of Graydon and Robyn Drown said the children then would rehearse stories to tell people about their injuries because if they told the truth they would receive more beatings.

In addition, one of the sons told detectives that none of the nine children has ever been to a doctor or dentist.

The Drowns, who have nine children, were arrested last week and are held on $180,000 bail.

More: Parents accused of abusing all 9 of their kids

Their nine, ages 6 weeks to 16 years, are in foster homes.

The Drowns also have three adult children who live away from home.

Officials learned of the alleged abuse from an anonymous source who passed on information he'd learned from the Drowns 14-year-old and 16-year-old sons.

Documents say the children feared their father and that on the day of the arrests the 16-year-old confirmed everything the anonymous source had said.

The Drowns appear in court again June 30.