In this file photo protesters shout slogans as they try to break through a police cordon during a protest after the death of a gang rape victim in New Delhi, India.

New Delhi - The key witness in the gang rape and murder of a 23-year-old woman in India was expected to be questioned by defence lawyers at a hearing on Wednesday.

Her 28-year-old male companion, injured in the attack, was called by the prosecution to testify on Tuesday against five defendants in a special fast-track court in New Delhi.

“The star witness will be cross-examined [on Wednesday]. Our questions will mainly revolve around his testimony and his identification of accused,” AP Singh, lawyer for two defendants, said.

All the defendants pleaded not guilty on Saturday to the charges that include murder, gang rape, abduction, destroying evidence and criminal conspiracy.

They could face the death penalty if convicted of murder. A sixth suspect is to be tried in a juvenile court, and faces a maximum sentence of three years at a correction home.

The young woman was raped on a moving bus and assaulted with an iron rod in the Indian capital on December 16. She died in hospital of multiple organ failure two weeks later.

The attack triggered protests in New Delhi and other Indian cities demanding improved safety measures for women. – Sapa-dpa