Standover tactics before $5m Vic fire

Evicted from a Melbourne warehouse after failing to pay rent, Jayden Tune warned his landlord "we're coming for you".

Then in a $5 million fire, the warehouse burned to the ground.

Tune, 32, has pleaded guilty to arson over the May 2021 blaze and to possession of unauthorised explosives - party sparklers ground into dust.

Tune and his partner rented a South Melbourne warehouse for two years from June 2020 for their business, Gentz Productionz.

But they were booted in February 2021 after failing to pay rent.

In response, Tune engaged in standover tactics targeted at the warehouse owner, his solicitor and a real estate agent, prosecutor Bruce Nibbs said.

In an email to the landlord's solicitor, Tune warned "touch a thing and it will not end very well".

It's alleged he or an associate texted the building owner to tell him "we are coming for ya dog".

To a real estate agent, Tune or an associate warned that the landlord's lawyer had quit "because of me and my brother from the Nomads MC" and asked for the landlord's details.

"If the dog does not contact me buy (sic) tomorrow me and the MC will take control of the property simple," a message said.

"Give me his address and info before I turn bad."

On May 5, 2021 Tune was spotted on CCTV leaving his Parkville home in a white cap and black bandana on a motorised scooter.

Just before 11.45pm he was seen at the warehouse, throwing something at the window which caused an explosion.

Flames blast back toward him and billowed from the window before he fled the scene on the scooter, according to Mr Nibbs.

Firefighters spent two nights and a day putting out the blaze which left such significant damage the cause of the fire could not initially be determined.

Fire investigators believe footage shows Tune pouring a flammable liquid through a window, leading them to conclude petrol and a cigarette lighter were used.

The building and its contents were totally destroyed, costing the owner $5 million in lost property, contents and income.

Tune's lawyer Chris Hooper said motivation for the blaze "would certainly appear to be a grievance, to say the least".

He said Tune had experienced profound difficulties in his life and as a consequences experienced periods of dysfunction, including drug use.

But he said Tune had worked hard to overcome setbacks and while results had been mixed, experienced showed he was capable of reform.

Tune will be sentenced next month.