Police protect key witnesses in Chaouk case

Victorian police are protecting the home of a key suspect in the killing of alleged crime family patriarch Macchour Chaouk to prevent revenge attacks.

Deputy Commissioner Ken Jones said the protection given to Ahmed Haddara, who was questioned and released by police after Chaouk's murder on Friday, was part of police steps to ensure there was no retaliation.

But he said it was the same protection offered to all Victorians.

"We've taken steps and measures to guard against further violence and anyone else that's thinking along those lines, just let us do our jobs - don't take the law into your own hands," Sir Ken told Fairfax Radio.

"I said the other day, protection is available to all the citizens of this great state and that will always remain so."

In the hours after Chaouk's killing, some family members were swearing to take revenge, while on Sunday one relative said there would be no wake for Chaouk "until other right people are buried".

Sir Ken reiterated his call for calm and said it was the "febrile atmosphere" around such killings that stimulated retaliation and police were working to dissolve that.

"We've got a lot of our officers out there talking to the community, talking to the various minority groups to make sure that we do reduce the tension and demonstrate to them that we are effective, we are the authorities, we're going to enforce the law and we're going to get justice," he said.

Sir Ken said investigators were making good progress and he was confident they would close the case.

"I don't want to get trapped into any timelines here, I don't want to put pressure on the investigators, they will get where they want to get to on this," he said.

Macchour Chaouk, 65, was gunned down in the backyard of his Brooklyn home on Friday morning.

He was farewelled by 100 mourners at the Preston Mosque on Monday under heavy police scrutiny.

Police said on Monday that Mr Haddara remained a "person of interest" in the murder investigation.