The 28-year-old male friend of the girl, who was brutally gang- raped in a moving bus, today appeared before a fast track court here to testify about the incident to which he is the sole eyewitness.

The youth, a software engineer, came in a wheelchair in the court of Additional Sessions Judge Yogesh Khanna after he was summoned as a prosecution witness in the case of December 16 gang- rape of a 23-year-old girl by six people.

The girl had died on December 29, 2012 in a Singapore hospital as a result of the grievous injuries she had suffered when she was sexually assaulted by six people, one of them a juvenile.

Before she had died, the girl had recorded her testimony before a magistrate. Her statement along with that of her friend's will be crucial for the prosecution.

Meanwhile, the Delhi Police has filed its supplementary charge sheet, including the post mortem report of the girl, in the case.

On February 2, all the five adult accused in the case pleaded not guilty to the charges framed against them by the fast track court.

The court had framed charges under various sections of the IPC for offences which include gang- rape, murder, attempt to murder, unnatural offences, dacoity, conspiracy and kidnapping.

Beside the victim's male friend, the court had also summoned three other prosecution witness to depose before the judge in the case.

The male friend's leg was seriously injured when the men on the bus had allegedly hit him with an iron rod.

According to the police, when the youth had tried to stop the gang, they hit him repeatedly and forced him to the back of the bus before they took turns raping the girl.

The police on January 3 had filed its initial charge sheet in the case.