In the ultra-competitive world of commercial television, presenters and producers can often be heard muttering the phrase they 'would kill for good ratings'.

In Australia it's just a saying, but in Brazil it turns out to be true.

There, popular television host Wallace Souza was accused of literally killing people to make his TV crime show more successful.

He's blamed for ordering and arranging murders so his cameras would be the first to capture the gruesome aftermath.

Wallace Souza was a popular TV host accused of orchestrating murders. (60 Minutes)

This Sunday on 60 Minutes , Karl Stefanovic reports the strangest story he's ever told. Did people lose their lives because Wallace Souza, the well-known host of television show "Canal Livre" craved higher ratings?

Stefanovic's assignment takes him to Manaus , one of the most dangerous cities in Brazil, to uncover the truth in this shocking tale of crime. He meets Souza's supporters and loyal viewers, who believe the TV host is innocent, and police investigators who say he's a cold-blooded murderer.

Manaus is one of the most violent cities in the world. (60 Minutes)

Wallace Souza's show "Canal Livre" was a curious mix of light-hearted entertainment and brutal crime. His audience seemed to have a particular appetite for gruesome murders, captured minutes after they occurred.

While the show was made to look like Souza and his team were simply following the trail of death and destruction paved through the city of Manaus, it wasn't long before disturbing allegations surfaced that it was organising the crimes it reported on.

Accused of setting up murders across the city, Wallace Souza went from TV celebrity to criminal mastermind.

Karl Stefanovic said this was the strangest story he has ever reported on. (60 Minutes)

The smoking gun in the case came from the testimony of a police informant. Moa Jorge was a former military cop who told police he was employed by Souza and was directed by him to carry out brutal executions for the benefit of "Canal Livre" and its ever-increasing audience.

But even tarnished with the label of murderer, Souza's supporters maintained he was not capable of killing.

None were more loyal than Souza's young son, Willace.

"I need to prove to the world that my dad was innocent," he tells Stefanovic.

"Who are the crazy people who kill people for ratings? This is insane."

Many people still believe Wallace Souza is innocent of the murder plots. (60 Minutes)

Local journalist Ana Sena says the evidence police have against Souza is overwhelming, but even still, the TV host's supporters will never accept he is guilty.

"People love him … his fans [will] never believe, no matter what you prove," she tells 60 Minutes.

Was Wallace Souza an innocent television star or a murderous mastermind?

Read more: The most dangerous cities in the world

Inmates inside Compaj maximum security prison, where Wallace Souza was held. (60 Minutes)