A man who ruthlessly stabbed and killed a Samoan man in Melbourne, Australia, last year is the grandson of a feared Melbourne gangster.

Kloud Allen, 24, fronted the Melbourne Supreme Court on Wednesday after pleading guilty to the manslaughter of 42-year-old handyman Andrew Sullivan.

According to media reports, Allen stabbed Mr Sullivan to death in an elevator at a commission housing block in the inner northern suburb of Carlton on January 16 last year.

The court heard Allen and a 15-year-old accomplice attacked Mr Sullivan with knives after an altercation broke out inside the elevator at the Drummond St building.

In a horrible twist, Mr Sullivan's dying body was sent down a floor where the elevator opened up to his partner Desiree Schmidt.

'I haven't gone near an elevator since that night,' Mr Sullivan's partner of nine years, Desiree Schmidt, told the court.

'He was stolen from me in the most brutal way possible,' she said.

'Since that day I have been living in a nightmare I can never escape, he was the love of my life, we were inseparable, I'm still so lost, completely and utterly lost.'

Residents attempted urgent first-aid before Mr Sullivan was rushed to the Royal Melbourne hospital where he died just after midnight.

Allen, a father of two, is the grandson of the deceased Melbourne drug kingpin Dennis 'Mr Death' Allen who ran his family's drug empire with murder and violence until he died in 1987.

His family, which included accused cop-killer Victor Pierce and crime matriarch Kath Pettingill, was fictionalised in the 2010 Australian crime film Animal Kingdom which was later adapted into a US TV series.

Kloud Allen fled to Queensland but was arrested and extradited back to Melbourne where he admitted to police he killed Mr Sullivan.

Allen, who was originally charged with murder, claimed he intended to stab Mr Sullivan in the arm and not in the abdomen in which an autopsy confirmed was the wound which proved to be the fatal blow.

The 15-year-old accomplice, who cannot be named for legal reasons, also stabbed Mr Sullivan several times and was handed a youth supervision order, which has since expired.

The manslaughter case involved multiple victim impact statements read to the court, including those from Mr Sullivan's mum, his partner and his siblings.

Mr Sullivan's mum Beverley Krieger said the 'pain is indescribable'.

'He was the apple of my eye, he was hardworking and selfless,' Ms Krieger said.

Other family members said Mr Sullivan would be 'sadly missed'.

A close friend told the court he has felt 'so sad since the loss of my friend'.

'He was kind, gentle and had much to give,' the friend said.