NRL great Paul Gallen says he and Sonny Bill Williams have a "life changing" $8m boxing deal on the table.

But Gallen is "filthy" at World Cup winning All Black Williams for apparently showing no interest.

State of Origin legend Gallen, who has become a pay-per-view boxing sensation in Australia, says the renowned British promoter Eddie Hearn is behind the deal.

Hearn is planning to expand the DAZN streaming service in Australia, and wants Gallen and Williams to clash twice in 2022 with each getting $2m per fight.

The 40-year-old Gallen, who has just beaten former Manly and Parramatta forward Darcy Lussick by a TKO, claimed that Williams was running from the so-called super deal.

The 36-year-old dual code superstar Williams - who has also retired from football - is unbeaten in eight professional fights, most held in Australia.

Gallen told the Daily Telegraph that his advisor Peter Mitrevski approached the Williams boxing camp about the fight deal, but it was not accepted.

"We're talking about life changing money - two fights, $4m each.

"Who else is getting that sort of cash. There are world champions who don't get that money. It's unbelievable.