The 19-year-old New Zealand Test loose forward has become hot property in the sport after an amazing debut season with Canterbury Bulldogs last year.
He is out of contract at the end of this season and, although fellow NRL clubs are barred from making an approach until June, Williams' agent revealed at the weekend a Super League club had submitted an offer that "blew us away".
"A couple of English clubs have registered interest in Sonny Bill and one has put a figure down on paper," said Chris Orr.
Wigan are thought to have made a move for Williams as a direct replacement for skipper Andy Farrell, who is poised to switch to rugby union.
But Wigan chairman Maurice Lindsay said: "Lots of people, strangely including chief executives of other Super League clubs, are suggesting that we are about to sign Sonny Bill Williams. This is simply not true.
"This has no doubt arisen because of the possibility that our captain Andrew Farrell might be joining rugby union. That situation is still not decided and we are certainly not trying to anticipate matters by prematurely negotiating a very expensive contract with Sonny Bill Williams."
Leeds, expected to announce a new contract for half-back Danny McGuire, have also denied making an offer for Williams.
"We are not the club who have blown away the player's agent with an offer," said Rhinos chief executive Gary Hetherington.
However, with their coffers boosted by record season-ticket sales and the prospect of a windfall from the sale of the Headingley cricket stadium to Yorkshire County Cricket Club, Leeds are thought to have the resources to plunder the transfer market.
The pairing of McGuire and Williams in the same team would make a mouth-watering prospect. Both players were outstanding in the recent World Club Challenge match between the Rhinos and the Bulldogs when Williams made a massive impact at Elland Road.
Canterbury are putting together what would be a lucrative five-year contract in the hope of keeping Williams in the NRL and they remain favourites for his signature.Like