The family of 22-year-old Aidan Becker, who was killed during a machete attack in Melbourne last week, have spoken out about their “unimaginable loss”.

The off-duty security guard died at Mernda railway station in Melbourne’s northeast on Friday night after intervening to protect a 14-year-old boy from a group of four machete-wielding teenagers.

A statement on behalf of Mr Becker’s family was released on a GoFundMe page on Monday, asking for privacy amid their “unimaginable loss.”

“The Becker family are grieving the unimaginable loss of their son and have asked that their privacy be respected as they come to terms with this devastating tragedy,” the statement read.

“The outpouring of support from the public has been deeply appreciated, and the family are grateful for the kindness and compassion shown during this time.“The family kindly asks that their wishes be respected and that they are given the privacy and space to grieve.”

Aidan Becker, 22, died after intervening to protect a 14-year-old boy from attackers. Aidan Becker, 22, died after intervening to protect a 14-year-old boy from attackers. Credit: AAP

It is understood that Mr Becker was attempting to protect a 14-year-old boy from being robbed when he was attacked.

He tried to walk away with the boy but was allegedly subjected to a “savage” attack involving punching, kicking and the use of blades, Homicide Squad inspector Nigel L’Estrange said on Saturday.

Mr Becker suffered life-threatening injuries and was treated by paramedics but tragically died at the scene.

Friend of the family, Chris Katelaris set up the GoFundMe page to “support Aidan’s loved ones during this devastating time.”

“Aidan’s actions showed the kind of person he was — brave, selfless, and willing to stand up for others when it mattered most. His family has now been left to face an unimaginable loss,” Mr Katelaris wrote.

“No family should ever have to endure a loss like this, and no act of bravery like Aidan’s should ever be forgotten.”

A makeshift memorial to Aidan Becker has been created by locals trying to make sense of his death. A makeshift memorial to Aidan Becker has been created by locals trying to make sense of his death. Credit: AAP

Following the attack, four male teens were arrested at the scene, three of whom have been charged with murder and armed robbery.

The eldest, Mike Pikos, 18, appeared before Melbourne Magistrates Court on Sunday morning but was not required to speak during the short hearing.

No other information was given during the brief session and there was no application for bail.

A 16-year-old from Whittlesea and a 17-year-old from Geelong were also charged with murder and armed robbery.

“This is just a tragic situation where our victim here is just a good Samaritan who was trying to do the right thing,” Det Insp L’Estrange said.

“He’s intervened, tried to protect this 14-year-old schoolboy, hasn’t been aggressive at all, tried to remove him from the scene, and as a result of his interaction, he’s now lost his life.”