"This tragedy has happened that I am old enough to bury a young man."

So said the mother of Brighton siege victim Kai Hao as she spoke of her family's grief over the death of her only son at the hands of a terrorist.

Mr Hao, a 36-year-old Chinese-born Australian, was shot dead by Yacqub Khayre at the Buckingham International serviced apartments on June 5.

Speaking through tears at an emotion-charged memorial service in Mount Waverley on Sunday, Yinping Zhang said dreams of a future with her son were shattered by the news.

"We planned to visit our family in mainland China later this year, but now, unfortunately, I have to take ashes of my son instead of him coming back for a wedding ceremony," she said.

"... All the things that belong to Hao Kai will be a reminder of his death to me. I have to be strong, strong, strong, I reminded myself, but I can't help this sorrow."

Ms Zhang was accompanied by her husband, Weidong Hao, who is in a wheelchair, at the memorial service organised by members of the Chinese community. The crowd of about 250 people collected almost $20,000 to help the family and also launched a Chinese emergency assistance fund. Mr Hao's father sat through most of the ceremony with his hand covering his face, crying.

Kai Hao, also known as Nick, had been working as a receptionist at the Bay Street apartments and was married only 15 days before he was killed in the terror attack.

Childhood friend Christine Wang, who also studied with Mr Hao at Monash University in South Gippsland, described him as a hard-working and humble person who was always ready to help, a man committed to looking after his parents.

At the service in the Mount Waverley Youth Centre, a large funeral wreath of white and yellow flowers was laid in front of a smiling black and white photo of Mr Hao.

Women and children made paper jasmine flowers to pin on the chest of mourners as a mark of respect.

Those gathered stood in silence in memory of the young life lost. Pledging support to the family, Federation of Chinese Associations president Junxi Su said the Chinese community said no to terrorism.

"As a migrant community, we will stand alongside others to build this country's prosperity, promoting social harmony, unity and peace," Ms Su said.

"Are we sad? Yes we are, because we have lost a young man who had a lot to offer to this country.

"Are we scared? No, we are not, because we know Australians love peace and they will not tolerate violence in any form and will stand together to protect our nation and our people."

Earlier, speaking on radio station 3AW, Prime Minister Malcolm Turnbull described the Brighton attack as heartbreaking.

Police found Mr Hao's body in the foyer of the apartment block after they were called to the scene by a sex worker taken hostage by Khayre.

The woman worked for an escort agency and was lured to the serviced apartments by Khayre, who had pretended to be a client before taking her hostage.

Khayre was later killed in a shootout with police and the woman was rescued.

Three police were injured in the terror incident. None of their injuries was life threatening.