Murdered gangster Carl Williams "had it coming," an expert on Melbourne's gangland scene has said.

Underbelly co-author and Melbourne Age senior crime writer Andrew Rule said that Carl Williams, 39, began a "chain of violence" which ended with his death yesterday.

Williams was in an exercise room in the maximum security Acacia unit at Barwon Prison when he was bashed to death by a fellow inmate, who was identified with the help of CCTV footage and subsequently charged with murder.

The man, who has name suppression, is charged with one count of murder and appeared in a Geelong court via video link from prison. He was remanded in custody and will next face the court on July 23.

The 36-year-old wore orange prison overalls and sat with his hands cuffed during the hearing.

In his newspaper column Rule said the fatal assault posed questions about Australia's prisons and justice system.

"That Williams was killed in one of Australia's most secure prisons suggests no one inside is safe if the stakes are high enough."

Williams' lawyer Rob Stary told ABC Radio he was "gobsmacked" over what happened because Williams was under constant monitoring while in solitary confinement or when released into common areas.

A prison officer was about 10 metres away when the bashing occurred and Williams returned to his cell before going into cardiac arrest.

Stary said Williams may have had information about corruption in Victoria and a number of corrupt people would have benefited from his murder in prison.

"He was a goldmine of information that unfortunately goes to his grave with his untimely death," he said.

The Melbourne gang wars were sparked by a 1999 incident in which Williams was shot in the stomach by Jason Moran during a meeting over an amphetamines deal.

Williams survived the botched shooting and swore revenge, setting in motion a war which claimed the lives of several leading crime figures.

The war served as the inspiration for the Underbelly books which were later turned into a hit television show.

Williams was believed to have been upset by his portrayal.

In a letter to his mother, obtained by Channel Seven, he wrote: "I don't mind them telling the truth about me, but telling lies and painting me out like some dickhead who is brain-dead, well, that's just bullshit."

Williams was allegedly responsible for at least seven murders, but in a deal with police he pleaded guilty to four and one charge of attempted murder. He was serving a 35-year sentence at the time of his murder.

Williams ordered the murder of Jason Moran, who was gunned down in front of his two young children as he and an associate, Pasquale Barbaro, sat in a car outside a football ground at Essendon in June 2003.

In October the same year Williams was responsible for the slaying of 38-year-old Michael Marshall, shot four times in the head in front of his 5-year-old son, apparently in revenge for the killing of one of Williams' associates.

Williams ordered the murder of Lewis Moran, who was shot dead at a Brunswick club in 2004.

Williams was also convicted of the 2007 killing of drug trafficker Mark Mallia, and of conspiring to kill Mario Condello, an underworld lawyer shot dead at his home in Brighton in 2006.

At his sentencing in 2007, Supreme Court Justice Betty King denounced Williams as a "cowardly" killer who ordered others to do his killing for him.

Without his guilty pleas, Justice King said she would have sentenced Williams to life without parole, something he would not have been eligible for until he was 71 years old.