A "hero" bystander who was filmed wrestling a gun from one of the Bondi Beach attackers has been named as 43-year-old Ahmed al Ahmed.

Video verified by the BBC showed Mr Ahmed run at the gunman and seize his weapon, before turning the gun round on him, forcing his retreat.

Mr Ahmed, a fruit shop owner and father of two, remains in hospital, where he has undergone surgery for bullet wounds to his arm and hand, his family told 7News Australia.

Fifteen people died and dozens were injured in the shooting on Sunday night, which took place as more than 1,000 people attended an event to celebrate Hanukkah. Police have declared it a terrorist incident targeting the Jewish community.

Mr Ahmed's cousin, Mustafa, told 7News Australia late on Sunday: "He is a hero, 100% he is a hero. He has two shots, one in his arm and one in his hand."

In an update early on Monday, Mustafa said: "I hope he will be fine. I saw him last night. He was alright but we're waiting to see what the doctor (says)."

His parents told the Australian Broadcasting Corporation that he had been shot four or five times.

"We pray that God saves him," his mother said.

His father added: "When he did what he did, he wasn't thinking about the background of the people he's saving, the people dying in the street.

"He doesn't discriminate between one nationality and another. Especially here in Australia, there's no difference between one citizen and another.

They said they had been separated from their son since 2006 when he came to Australia. They had travelled to Sydney from Syria a couple of months ago.

Police say that the two shooters involved were a father and son aged 50 and 24.

They confirmed that the 50-year-old man died at the scene while the 24-year-old remains in hospital in critical condition.

The footage of Mr Ahmed's intervention has been shared widely online.

It shows one of the gunmen standing behind a palm tree near a small pedestrian bridge, aiming and shooting his gun towards a target out of sight.

Mr Ahmed, who was hiding behind a parked car, is seen leaping out at the attacker, whom he tackles.

He manages to wrestle the gun from the attacker, pushes him to the ground and points the gun towards him. The attacker begins to retreat back to the bridge.

Mr Ahmed then lowers the weapon and raises one hand in the air, appearing to show police he was not one of the shooters.

The same attacker is later seen on the bridge picking up another weapon and firing again.

Another gunman also continues firing from the bridge. It is unclear who or what they are aiming at.

At a news conference late on Sunday, New South Wales Premier Chris Minns paid tribute to the bravery of Mr Ahmed, who was unnamed at the time.

"That man is a genuine hero, and I've got no doubt there are many, many people alive tonight as a result of his bravery."

Australian Prime Minister Anthony Albanese said: "We have seen Australians today run towards danger in order to help others.

"These Australians are heroes, and their bravery has saved lives."

Speaking at a White House Christmas reception, US President Donald Trump also praised Mr Ahmed, saying he had "great respect" for him.

"It's been a very, very brave person, actually, who went and attacked frontally one of the shooters, and saved a lot of lives," he said. (BBC)