The mother of the innocent Melbourne apartment receptionist killed by an ISIS-inspired murderer has tearfully explained she is now “helpless” without her son.

Police said Kai (Nick) Hao, 36, was “in the wrong place at the wrong time” when he was fatally shot by siege gunman Yacqub Khayre the lobby of the Brighton serviced apartments.

Mr Hao was an only child. (9NEWS)

Mr Hao’s mother spoke to the media this afternoon to express what have been the “saddest and darkest” days in her life.

“When we came to Australia, we were looking forward to a family reunion,” a translator said on behalf of Mr Hao’s mother, who arrived in Melbourne with her husband in September last year.

“But after the incident, the past two days have been the saddest and darkest in our lives.”

Mr Hao's mother wept during the press conference this afternoon. (9NEWS)

She explained that Mr Hao was her only child, and she and her husband had poured most of their savings into sending him to Australia in 2002.

“My husband and I are both retired in China. We spent most of our savings on our son to send him to Australia,” she said.

“We are both old, and now we have to bury our son. It feels like the end of the world… I have to take my son back to China in a box.”

She told reporters that she and her husband both have physical ailments and cannot speak English.

“Our hope is gone. We have no-one to rely on in our old age,” she said.

“We have nothing left.”

Mr Hao’s mother was overcome by emotion as she confirmed her 36-year-old son had married in Melbourne just four weeks ago.

The 36-year-old was married just last week. (9NEWS)

“We were planning to host a huge wedding banquet in August, in China. But now I have to go back with his remains instead.”

She expressed immense hatred for Khayre, who was on parole when he killed Mr Hao.

Yacqub Khayre outside court in 2010. Khayre and another man were acquitted by a Supreme Court jury, of planning an alleged terrorist attack on the Holsworthy army base in Sydney. (AAP)

“I cannot tell you how sad I feel, or how much hatred I have toward the terrorist…he tore my family apart,” she said.

“Such an incident in Melbourne shows the world is full of uncertainties and dangers.

Floral tributes outside Mr Hao's workplace on Bay Street, Brighton. (9NEWS)

“Terrorist groups are reaching all corners of the world… we hope that Australians and Australian-Chinese communities can unite and together we can fight terrorism.”

She thanked Victorian Police and the local community for their assistance and communication throughout the incident.

Mr Hao’s mother and father had applied to live in Melbourne, but their plans are now on hold as a result of their son’s death.

The two police officers from the Special Operations group injured in Monday's attack continue to recover at The Alfred Hospital.