A report in a rugby league newspaper suggested the Rhinos were set to play Aviva Premiership club Leicester Tigers, possibly at Arsenal's Emirates Stadium in June.
Hetherington played down that prospect but admits he held talks with former Leicester and Australia coach Bob Dwyer, a big advocate of the cross-code experiment, during a recent trip to Australia and that the Super League club are open to the idea of a challenge game.
Hetherington said: "I met with Bob Dwyer and I was fascinated by the set of rules that they have devised.
"There have been initial discussions. We are receptive to this type of challenge, subject to RFL approval and I know our players are too.
"Money is not the motivator for us and we would donate any profits to rugby charities, but the contest could generate enormous interest around the world and raise the profile of both codes."
Under the proposed regulations for a hybrid game, rugby league is played while a team works their way out of their own half, with rugby union rules taking over as they entered the opposition half.
A hybrid match was held in Sydney last May between two leading school teams from each code and there are plans for an NRL team to take on the All Blacks in Australia later this year.