John Robert Griffiths ran his fraud through Gumtree from his brother's home in Victoria's Indigo Valley, fuelled by a gambling addiction.

His sibling, and his sibling's partner, had no idea what he was up to inside his room at their house.

Starting on August 7, 2013, Griffiths used the website to place advertisements for property he didn't own.

His first victim agreed to transfer $1630 into his bank account for an Apple Macbook.

The man contacted Griffiths who gave multiple excuses when asked why it hadn't arrived.

The matter was reported to police when it became apparent the laptop would never be sent.

It was a scam he would continue to commit another 98 times until last September.

Equipment including laptops, DJ gear and other electronic items were offered for sale.

One man was duped out of $22,015 and another lost $16,525, with most victims stung for a few thousand dollars.

Griffiths, who is wanted in several states and territories, used a string of aliases, bank accounts and email addresses to run the fraud, and changed phone sim cards every six to eight weeks to avoid detection.

Some of the phones were registered in family members' names.

He had two online bank accounts based in the UK which he also used in a bid to thwart authorities.

But the case came to the attention of a Wodonga detective in 2018 and would eventually lead to a raid on Griffiths' residence.

The detective had established that one of the phones was linked to a Wodonga home which had been occupied by his mother.

A check of an IP address used in one of the cases was linked to his brother's girlfriend and the Indigo Valley home.

Officers raided the house on December 8 last year and Griffiths was co-operative, giving over his passwords to investigators.

He said his gambling addiction had "snowballed" a month after he was released from jail in Western Australia in 2013 and said he was a "degenerate" gambler.

He deluded himself into thinking he would win enough money to pay back his victims.

"Many of them .... who spoke to me on the phone, entrusted (me) with what I've done, and I took livelihoods away from them, I took their money away from them, and it was never meaning to get this bad," he said.

He has no way of repaying his victims.

Griffiths has remained in custody since his arrest and will be sentenced on Thursday on 101 charges.