How did the Delhi gang rape accused die in prison?
Delhi's Tihar prison promises "safe and secure custody" of inmates, according to its website.
But the death in prison of a man accused in the gang rape and murder of a student in Delhi has raised questions about security in what is South Asia's largest prison.
Ram Singh's death is also a huge embarrassment for the authorities. "So, one can commit suicide under the watchful eyes of the Tihar Jail. Great!," tweeted writer and activist Meena Kandasamy.
The 55-year-old jail houses more than 12,000 inmates, although it has an official capacity of about 6,000. It is also India's most high-profile prison, where a number of prominent politicians and businessmen facing trial in corruption cases are being held.
Authorities say Tihar is one of the most secure and modern prisons in India. It is equipped with CCTV cameras, mobile phone jamming devices, scanners and metal detectors.
The sprawling campus hardly looks like a jail. Visitors are shown a model prison where inmates make bread, shoes, furniture, paper and clothing, among other things.
In January, lawyers representing the accused in the Delhi gang rape case had complained that their clients were being tortured. Tihar spokesperson Sunil Gupta had then told the BBC that the safety of the five men was "guaranteed".
So what went wrong?
Mr Gupta says Ram Singh was not on suicide watch, and that he "used a blanket in his room as an improvised rope" to kill himself.
Mr Singh's lawyer and family don't seem to believe the official account: they have been telling the media that he was "murdered" in prison.
His lawyer told the BBC that his client, who had pleaded not guilty, appeared to be in good health the last time he saw him on Friday, and that he had no reason to commit suicide.
Suicides and murders in Indian prisons are not uncommon.
A total of 1,436 inmates died in 1,393 prisons in 2010, the latest year for which figures are available. Ninety-two of them died of "unnatural causes", including suicide and murder.
Most of the "unnatural" deaths were due to suicide (68) and murder by fellow inmates (12).
Inmates have died because of lack of medical care too. In 2011, the Delhi High Court ordered the authorities to pay compensation to the wife of biscuit tycoon Rajan Pillai who died in Tihar in July 1995 for lack of proper medical care.
The court also said deaths at Tihar were not an "uncommon phenomenon".
A report by the People's Union for Democratic Rights in 2011 raised questions about the rights of prisoners in Tihar with "respect to receiving visitors, access to medical care".
Senior prison officials I spoke to say they are surprised to hear that Ram Singh was not put on suicide watch.
They say high profile prisoners - usually on trial or convicted in murder or terrorism-related cases - are often kept under suicide watch and given more protection as they face massive media coverage and are deemed to be at risk from other inmates.
In many cases fellow inmates are instructed by their jailors to keep a watch on such prisoners, I am told, and guards are posted outside the cell, which may also be under CCTV coverage.
Some years ago I remember sitting in a jailor's room in a Calcutta prison and watching grainy black and white CCTV footage streaming from a tiny cell housing Aftab Ansari, who is serving a death sentence for his involvement in a 2002 gun attack on a US cultural centre in the city.
More than 10,000 inmates have died in prisons in India since 2000, hundreds of them in "unnatural" ways. Deaths in custody are a terrible blot, and clearly a lot more needs to be done to protect the lives of inmates.