In Sunday's finale episode, the Sydney mates are seen high-fiving millionaire bidder Adrian Portelli, before the auction had even begun.

Omar and Oz then emerged as the winners of The Block’s ‘Treechange’ season, earning by far the biggest win in the show’s near-20-year history with a profit of $1,686,666.66 for their luxe home in Gisborne, country Victoria.

The victory came after serial Block bidder Danny Wallis, who ended up buying the three homes that actually sold at auction, became locked in a battle with two other bidders, among them Portelli.

With the battle driving the price up, Portelli, who arrived in a Lamborghini and greeted Omar and Oz with a hug, was eventually outbid by Danny Wallis.

With Portelli left empty handed, he promptly left the auction site and expressed no interest in any of the other properties, despite beginning Omar and Oz's auction way above the reserve price.

These behaviours have since raised questions about how well Portelli knew the Block winners, given they were on good enough terms to share a pre-auction high-five.

“Oz and I got together with our agents a fair bit and they mentioned we had to reach out to all our networking and see who would potentially be able to come to the house and have a look at it,” Omar told Daily Mail Australia.

“We reached out to a mutual friend (Portelli) who said he might be keen. He’s watched the show. He’s seen our house and he absolutely loved it when he did come and see it a few weeks ago.”

He added that he was “disappointed” people felt Portelli may have been a ‘dummy bidder’ designed to push the price of the home up.

“He also saw another couple of houses and unfortunately for the them he wasn’t interested. I’m pretty sure he went to house three or four on auction days,” Omar added.

Image credits: The Block