They also seized cannabis plants and equipment from a clandestine laboratory from the home, on Beverley Street in Kings Park.

They located the weapons at a factory on Derrimut Drive in Derrimut.

The Echo Taskforce swooped on the two properties about 7am on Wednesday, a police spokeswoman said.

The spokeswoman said the searches were part of an ongoing investigation.

Chad Xuereb, 31, faced an out of sessions hearing on Wednesday night where he was remanded in custody.

He has been charged with possessing a quantity of firearms that could be trafficked, 11 counts of possessing a handgun and three counts of possessing a long-arm weapon.

Mr Xuereb has also been charged with possessing materials to manufacture a drug of dependence, cultivating and possessing a drug of dependence and possessing cocaine.

He made some admissions about manufacturing weapons during an interview at his warehouse but denied knowing about the drugs or evidence of a clandestine lab found in a hidden room at his electrical contracting warehouse, the bail hearing was told.

Police allege they found five weapons hidden around Mr Xuereb's King Park home, including a loaded sawn-off shotgun secreted inside his couch.

Three more guns were discovered, two hidden behind his fridge and another in a wardrobe.

Police also seized two tasers, two hunting knives, knuckledusters, eight cannabis plants, pepper spray and steroids from Mr Xuereb's home and business.

Reading the police summary against Mr Xuereb aloud, the detective said he had fitted surveillance cameras to the outside of his house, as well as to an electricity pole across the street, all of which he was monitoring from his bedroom.

In his office at the Derrimut warehouse, police allege they discovered schematics for making guns as well as nine "bolt guns".

In applying for bail, Mr Xuereb said there had been threats on his life and that he'd taken steps to protect himself. Earlier in the year his appendix had burst and eight weeks later he was involved a car crash, he said.

"I took it upon myself to protect myself."

Mr Xuereb told the bail justice he had allowed an ice-addicted friend to stay at his factory and that there had been people coming and going in recent weeks without his knowledge.

"My factory is open to a lot of people," He said. I've taken the rap for a lot of people. I probably should have said no."

"I regret it. I was thinking in the cell that I was trying to help people; if I'd said no I would have been better off."

Bail Justice Anthony Mordin said he was concerned about the amount of items that had been found and denied Mr Xuereb bail.

Mr Xuereb will face the Melbourne Magistrates Court tomorrow morning.