Authorities in India say the main suspect in the gang rape of a woman on a New Delhi bus has committed suicide in prison.
Sunil Gupta, a spokesman for the Tihar Jail, said suspect Ram Singh hanged himself in a New Delhi cell after making a noose out of a blanket.
Gupta said Singh was in a cell with three other inmates and an inquiry was ordered into his death.
The dead suspect's family and defense attorney suggested Singh, who was said to have been under suicide watch, had been killed, and urged authorities to carry out a full investigation.
Singh was accused of driving the bus on which a 23-year-old student was raped and assaulted by a group of six men in December.
The assault sparked a huge wave of outrage and protests across the nation demanding better protection for women. The victim died after suffering massive internal injuries.
Women's rights activists have expressed doubts over how such a high-profile prisoner could have taken his life in Tihar Jail, the most modern maximum-security prison in India.
"The whole world, India, and we were waiting that these people would be hanged. Now if the main suspect hangs himself while in custody inside the Tihar Jail, where security is supposed to be really tight, then this is a very surprising thing," said Barkha Singh Shukla, the head of the Delhi Commission for Women.
"As far as I know, he was kept in a separate barrack. So, I feel that this is very surprising and raises questions on the police authorities."
Singh was facing charges of murder, gang rape, abduction, destruction of evidence, and criminal conspiracy in a special court trial that began on February 5.
He had been due to appear in court on March 11.
Five men including Singh were charged with the crime and have been appearing in a special court set up to deliver quick verdicts.
A sixth suspect, a 17-year-old, is being tried in a separate juvenile court.
With reporting by AP, dpa, and AFP