CLEVELAND, OHIO (AFP) - A Cleveland man accused of holding three young women captive for a decade pleaded not guilty on Wednesday to charges of kidnapping, rape and murder for beating one pregnant captive until she miscarried.

Ariel Castro, 52, could face the death penalty if convicted of the aggravated murder charge, which is a capital offence in Ohio if it occurs in connection with a kidnapping.

Castro's lawyer entered the plea on his behalf in a brief arraignment. He shuffled into the courtroom in an orange prison jumpsuit with his head bowed and did not say a word.

The stunning case came to light after Ms Amanda Berry, 27, managed to escape with her six-year-old daughter by calling out to a neighbour for help through a locked front door. Police found two more women huddled in the house: Ms Gina De Jesus, 23, and Ms Michelle Knight, 32. All three had been snatched in separate incidents in 2002, 2003 and 2004.

Most US states have fetal homicide laws that allow prosecutors to punish those who harm pregnant women while also protecting the woman's right to carry out a lawful abortion. Kidnapping and rape are not capital offences despite the horrifying ordeal imposed on the three women who were snatched off the street with a promise of a ride home at the ages of 14, 16 and 20.

The 329-count indictment handed down last week offers glimpses of their suffering, even though it only covers the first five years of their captivity.

Ms Knight, the first to be snatched, was chained to a post in the basement, repeatedly raped and beaten and impregnated at least four times.

Ms Berry tried to escape the night she was kidnapped but was overwhelmed and then raped. Her legs and mouth were bound with tape, she was chained to a pole in the basement and Castro put a motorcycle helmet on her head, the indictment said. At one point that night, he wrapped a vacuum cord around her neck.

Ms De Jesus was also chained and bound with tape in the basement, beaten and sexually assaulted on the night she was kidnapped. But it was about a month before Castro forced the 14-year-old to have sexual intercourse.

A leaked police report revealed even more horrifying details.

Ms Knight told police that Castro "would make her abort the baby", the police report read. "He starved her for at least two weeks and then repeatedly punched her in stomach until she miscarried."

Castro brought in a plastic kiddie pool and forced Ms Berry to give birth in it in order to contain the inevitable mess, the women told police. He also forced Ms Knight to assist and told her "if baby died... he'd kill her". At one point on that terrifying day on Dec 25, 2006, the newborn girl stopped breathing, and Ms Knight "breathed for her", giving mouth-to-mouth resuscitation. A DNA test proved that the child is Castro's daughter.

The women said they were chained in the basement during their early years of captivity, but eventually were allowed to live unchained upstairs behind locked doors.

Police were unsure how it was that none of the people who would visit the unassuming house at 2207 Seymour, including Castro's family, realised what was going on behind closed doors.

"Ariel kept everybody at a distance," deputy police chief Ed Tomba said shortly after the arrest. "The control that he may have had over those girls, we don't know that yet. I think that's going to be - take us a long time to figure that out."