Investigators found the remains buried in a large, man-made bunker inside a shed at the rear of a property at Kudla on Tuesday afternoon.

But Detective Inspector Mark McEachern said it was too early to say if the body belonged to Murphy, 38, who has been missing for almost two months.

Police are treating the find as a homicide investigation and will conduct further forensic tests on the remains, which were found in a hole several metres deep, to identify the body.

“We’ve spoken to Mr Murphy’s relatives and advised them there’s been a development but we can’t confirm to them that it’s Steven,” Det Insp McEachern said.

Investigators on Sunday night received a tip-off that there might be a body at the premises, information which led to the discovery of a cannabis crop and an unauthorised firearm.

Police said they knew of no obvious connection between Murphy and a 45-year-old man arrested at the Kudla residence in relation to the drugs and gun.

The man was charged with possessing a firearm without a licence, possessing an unregistered firearm and ammunition, cultivating a commercial quantity of a controlled plant and possessing prescribed equipment.

He was refused bail and appeared in Elizabeth Magistrates Court on Monday.

Police said they found 20 cannabis plants being hydroponically grown in the shed behind the house.

Det Insp McEachern said police were keeping an open mind about the identities of the person whose remains were found and whoever was responsible for the death.

Police posted an appeal in relation to Murphy’s whereabouts on Facebook on March 18.

It said he was last seen at Kudla on February 15 and they had concerns for his welfare.

-with AAP