Former courier and now multi-millionaire Gary Baron admitted that he was the mystery winner of a $16.6 million Powerball draw when confronted by angry members of a lottery syndicate on Sunday afternoon.

Mr Baron told his former co-workers that he had won a stake in the $50 million jackpot with a separate ticket to the one he purchased on behalf of the syndicate.

Standing outside his Geelong property in a dressing-gown on Sunday afternoon, Mr Baron insisted he had evidence to substantiate his claim, which had been handed over to his lawyer.

The 49-year-old had repeatedly denied winning the massive windfall to several members of a 16-person syndicate, who had entered the lottery on a regular basis since 2009. He is understood to have told another former colleague that he had received a significant inheritance.