He is said to be the highest paid player in the Super League, earning £200,000-£250,000 ($362,000- $453,000) a season at Wigan, who upgraded his contract in 2011.
Tomkins is contracted to Wigan until 2016 but is believed to be considering a move after this year's Rugby League World Cup.
The Warriors would have competition for his signature, as English rugby clubs are also interested in the 24-year-old.
Tomkins' older brother Joel made the switch to rugby union in 2011 (from Wigan to Saracens).
Sam Tomkins made a one-off appearance for the Barbarians in 2011, scoring a try in their 60-11 defeat against the Wallabies.
Super League club Salford had a huge bid for Sam Tomkins turned down earlier this year and other NRL clubs are said to be in the mix.
Tomkins has scored 124 tries in 136 matches for Wigan, including an incredible 16 hat-tricks. He has also managed one try per game at international level (18 from 18), though many of these have come against France.
Now established in the No1 jersey, the 1.80m Tomkins would offer great utility value. He made his name in the halves, scoring 15 tries in 27 appearances in his first year in Super League in 2009 and was named Wigan's player of the year. Midway through the following season, then-Wigan coach and current Rabbitohs supremo Michael Maguire switched him to fullback. By the start of the 2011 season, Tomkins was the club's first choice fullback.
Apart from the early years, when Dennis Betts and Andy Platt were lured to Mt Smart, the Warriors have not generally pursued players from the United Kingdom.
But the success of recent recruits such as James Graham (Bulldogs), Gareth Widdop (Storm) and the four Burgess brothers at Souths (along with a favourable exchange rate), has made British talent more appealing to NRL clubs.
Coach Matt Elliott also has an extensive Super League background while Bell was a Wigan legend as a player and has also filled coaching roles there.
As well as scouting players, Scurrah and Bell were on a general fact-finding mission.
The Warriors hope to organise a 'sister club' arrangement with a top Super League side and are also looking into other commercial opportunities in the Northern Hemisphere.