Police says greed is the motivator behind the death of Brisbane man Tony McGrath, whose body was found under his home nine months ago.

Greed is behind the murder of a Brisbane referee found under his home with a gunshot wound to the head.

There’s finally been a breakthrough in Tony McGrath’s murder, nine months after his gruesome death.

A 38-year-old homeless man has been charged with his murder after being arrested in his car in at the Yatala Pies shop, south of Brisbane.

Police are questioning others over the murder and are expecting further arrests.

They wouldn’t confirm if the man was hired as a hit man but said the “persons of interest” were to gain financially from the rugby league referee’s death.

It’s the second time there has been an attempt on Mr McGrath’s life, after a fire in October 2012.

The 38-year-old man has also been charged with stupefying Mr McGrath and attempting murder by setting his Woolloongabba home alight.

Police say greed lead to Mr McGrath’s death, but wouldn’t detail how much could be gained by the murder.

“We believe that the motive for the murder is financial,” Detective Inspector Damien Hansen of the State Crime Command Homicide Group said.

Mr McGrath, 57, died of a single shot to his head and may have been dead for more than two days before his body was found by a friend on May 21.

Police described him as a “loner” who had no family apart from his sister and said his lack of close relationships made it hard to track leads.

He had been single for many years and was retired after a long career with the tax office.

Not long before his death he had been appointed president of the Brisbane Rugby League Referees Association.

“I’d say he was more than comfortable,” Rod Kemp Detective Inspector at Mount Gravatt said.

“He was reasonable citizen, quite wealthy in his own right I guess, without saying he was overly wealthy.”

A 46-year-old man was arrested on Wednesday night at Terranora who police say is a person of interest, however he’s yet to be charged over the murder.

A woman who use to own a brothel in Tweed Heads has also been spoken to and a number of properties will be searched in the coming days.

Police say persons of interest are more friends than business associates.

“It is a very complex investigation. There are a number of persons of interest and that could increase in the coming days,” Det Insp Kemp said.

The 38-year-old man charged with murder is also charged with robbery with violence whilst armed, attempted murder, arson, stupefying in order to commit an indictable offence, entering premises with intent and weapons act offences.

He was due to appear in the Brisbane Magistrates Court on Thursday.