California prosecutors have detailed allegations of horrific abuse by the parents of 13 children held in shackles at their home.

David Turpin, 56, and Louise Turpin, 49, face charges of torture, abuse and false imprisonment, Riverside County district attorney Mike Hestrin told reporters.

They are due to appear in court to be formally charged.

Mr Hestrin said all 13 of the couple’s children were severely malnourished.

He said the teenager who fled from the house earlier this week to raise the alarm had planned the escape with her siblings for two years.

She fled through a window with a sibling, who then became afraid and returned to the house, he added.

The couple’s children, who are aged between two and 29, have been treated in hospital since being freed.

Mr Hestrin said that the couple had punished their children by tying them up – first using ropes and later using chains and padlocks.

He said the punishments would last weeks or months at a time.