Waleed Aly delivers his most fierce wake-up call yet, and we are definitely listening.

Waleed Aly has now become well-known across Australia for his powerful editorials.

We all remember his defiant statement that “ISIS is weak” or the incredible “Show Me The Money” plea on domestic violence, but now, he has brought to light another horrific issue facing Australians.

Our treatment – or mistreatment – of Indigenous persons in custody.

You may have thought this was “dealt” with.

Wasn’t there a Royal Commission back in the 1990s? Weren’t there hundreds of recommendations to completely stop these preventable deaths?

The answers to those questions are all true, but as Aly pointed out on Friday night – Indigenous people are still dying in custody, and we haven’t even realised.

In fact, as The Project co-host begins, just last month Rebecca Maher was left to her death in a Hunter Valley police cell.

Rebecca Maher who died last month. Image via Tenplay.

The mother of four was picked up by police and detained after she appeared either drunk or disoriented, and she was locked away.

She was put into custody not for committing a crime. According to police, it was for her own protection.

Six hours later, Maher died.

It took another six hours for the family to find out.

"Just think about that," Aly said. "Imagine police found your mum dead first thing in the morning, and you weren't told until after lunch."

Maher was the first Indigenous person to die in a NSW cell in 16 years - since 2000.

The reason why so many deaths have been prevented in this time, in the eyes of Aly, is because of one policy.

The Custody Notification Service was introduced to 2000 in NSW, which alerts the Aboriginal Legal Service that an Indigenous person is in custody.

Once the ALS have that information, they can inform the family, find out if they require any medication, provide legal advice - check for their basic needs.

Because Maher wasn't arrested, rather "detained for her own safety", the police didn't technically have to send an alert to the ALS.

And as Aly points out, "Had she actually committed a crime, she'd had more chance of being alive today."

You might be thinking that Maher is a once off case. A slip-up in the system.

But, it's not.

In 2014, another woman, Ms Dhu, was locked up in South Headland Police station, WA, after failing to pay fines.

Ms Dhu. Image via Tenplay.

At the time she was jailed, the 22-year-old had suffered a cracked rib after alleged domestic violence. For more than two days, she suffered horrendous pain to the point where she wasn't able to walk.

Ms Dhu was left to her death, passing away from pneumonia and staphylococcal septicemia that was caused by her broken rib.

Since the Royal Commission into Aboriginal Deaths in Custody, the statistics have gotten progressively worse for Indigenous Australians.

Despite only being two per cent of the national population, they occupy 28 per cent of the prison population. They are 13 times more likely to end up in jail than non-Indigenous people.

With shocking facts like this, you would think we would know.

You would think it would be making news every single night.

But, as Aly so powerful punches home - do we even care?

"I learned in school that the last person to receive the death penalty in Australia was Ronald Ryan, hanged in 1967.

"But the truth is, we still have the death penalty.

"Clearly, death is sill a penalty we're okay with in this country. As long as, one, the person dying is Indigenous, and two, their carers don't illegally murder them outright....

"And this is a penalty that we've administered almost 400 times in the last 25 years. That's 400 times since a Royal Commission gave us 339 ways to stop this.

"In other parts of the world right now, people are protesting that black lives matter....

"But what I want to ask you, right now, knowing everything I've just told you is: do black deaths matter? I really hope the answer is yes."