Ram Singh, the alleged mastermind of the Delhi gang-rape that shook India, reportedly committed suicide in the Tihar Jail here Monday morning. His family alleged he was murdered.

According to jail officials who refused to speak on record, Ram Singh, 35, was seen hanging at 5.45 a.m. by a Tamil Nadu policeman in the prison's Jail no. 3 -- 84 days after the horrendous gang-rape.

Ram Singh, who drove the bus in which the 23-year-old was brutally raped, used a part of a bed linen to hang from an iron grille eight feet high in his 15x12 rectangular cell, official sources told IANS.

While three others in his cell were asleep in the rear portion, Ram Singh apparently killed himself nearer to the entrance where the ceiling is only eight feet high. The rear of the cell is 10 feet high.

This enclosure has a transparent asbestos sheet on the roof -- to let in natural light. Underneath it was the iron grille.

Ram Singh reportedly reached the iron bars by standing on a bucket.

Home Minister Sushilkumar Shinde called the death "a major security lapse" but refrained from using the word "suicide". Delhi Police made no comment.

The rape victim's 20-year-old brother expressed shock.

"Ram Singh should have faced the gallows. He should have been hanged publicly. Ram Singh was aware that there was strong evidence against him and he could get the death penalty," the brother told IANS.

The Tihar Jail put out a brief statement.

"The matter is being inquired into by the judicial officer. The exact cause of death would be known after (the) report which also includes post-mortem examination," it said.

Ram Singh's father alleged he was murdered and demanded a Central Bureau of Investigation (CBI) inquiry.

"He was killed and hanged in the jail. He told us several times that he was threatened in the jail. We lodged a complaint... It was not suicide," a stunned Mange Lal told reporters outside Tihar Jail.

V.K. Anand, his lawyer, also alleged foul play and demanded an impartial inquiry. He said that Ram Singh was not depressed as was being made out by prison officials.

Ram Singh's death led to several versions until the home minister spoke to the media. An earlier report claimed he hung himself from a window using his pyjama.

Shinde said Ram Singh used a 'durri" (rug) to hang. He said a magisterial inquiry had been ordered.

Jail officials refused to identify the three men who shared his cell.

Ram Singh was arrested from a Delhi slum where he lived Dec 17 -- a day after he and five others, including a juvenile, raped the physiotherapist trainee, a crime that shook the collective conscience of the country and made for shocking news across the world.

Ram Singh, known to suffer from deformity in his left hand, was the bus driver which the young woman and her male friend boarded Dec 16 night in a south Delhi neighbourhood.

While the woman was brutally raped, her friend was thrashed. Both were flung out of the bus, bleeding and without clothes. The woman died 13 days later in Singapore.

The incident sparked off widespread protests in India.

Tihar officials had earlier said that Ram Singh was on "suicide watch", after he and the other accused reportedly became depressed. The watch was lifted later, they said.

Ram Singh, who had confessed to the crime, had been charged on 13 counts. One of the five accused is his younger brother Mukesh. All are being tried in fast-track court.

Lawyers said Ram Sing's death would not affect the trial. He was supposed to go to the court Monday.

The others accused in the case are Pawan, 19, and Akshay, 29, who are held in Tihar Jail No. 4, Vinay, 20, and Mukesh, 26, both in Jail No. 7.

The sixth accused is a juvenile, lodged and being tried separately.

Tihar Jail is India's biggest and houses over 12,000 prisoners. Its internal secuirty is the task of the Tamil Nadu Police. The outer security is managed by other agencies.

(IANS)