Ram Singh, driver of the bus and allegedly the one who led the brutal attack on the victim, was found hanging at a cell in Jail No 3 around 5.45 a.m.
Reacting to the development, the victim's brother pointed out that the bus driver was well aware of the prosecution building a strong case against the five accused including Ram Singh and having enough evidence to incriminate all of them.
"He was aware that the death penalty would be given to him and therefore decided to die now... he should have been hanged in public... His suicide seems to be unfair," the student's brother said.
Calling for immediate steps to prevent the other accused from similarly ending their lives, he stressed that the rapists must be executed publicly.
Expressing satisfaction over the ongoing trial in the fast track court here, he added that the judgement is likely to be delivered sometime next month.
The victim's father was upset over the fact that the authorities allowed Ram Singh to "choose the way he wanted to die". Slamming the jail officials for this lapse, he wondered whether it would negatively impact the case.
His wife told newspersons that she only wants justice for her daughter whom the entire world refers to as "Nirbhaya" since her real name cannot be revealed as per Indian law.
About Ram Singh's suicide, the victim's mother noted that "Maybe the guilt killed him."
A magisterial inquiry has been ordered into the incident as Ram Singh's relatives have ruled out the possibility of the 35-year-old hanging himself given the fact that one of his hands was fractured in an accident some years ago. Doctors had to insert a rod into the badly damaged limb at that time.