Might have been Nick Du Toit

I think the player your Dad is talking about was Attie Van Heerden,a South African winger who signed for Wigan in 1923.
His background was follows,he represented South Africa in the 1920 Olympics in the 400 metre hurdles (hence the reputation for Hurdling players) he then represented S/A at Union before signing for Wigan as a winger.
I first started watching Wigan in 1954 and I remember the older fans talking about him and his hurdling prowess.

A little more information about Van Heerden,he played in a Cup Final for Wigan against Oldham at Rochdale in 1923/24.
Over the years people have told the story of him diving between the legs of a Police Horse to score a try,the horse was stood on the try line trying to control the very large crowd.
Below is an extract of the incedent told in Wiki.

"Attie van Heerden's try was scored between the posts behind a police horse that was on the field of play attempting to keep the 41,831 crowd at bay."

Quote Fujiman="Fujiman"my dad used to tell me billy b did this but not heard anyone else say so'" When he said Billy B, did he mean Billy Batten? He was probably the most famous exponent of jumping over an opponent whilst playing for Hull FC in the era around the time of the first world war. en.wikipedia.org/wiki/Billy_Batten

Quote Fujiman="Fujiman"my dad used to tell me billy b did this but not heard anyone else say so'" When he said Billy B, did he mean Billy Batten? He was probably the most famous exponent of jumping over an opponent whilst playing for Hull FC in the era around the time of the first world war. en.wikipedia.org/wiki/Billy_Batten

Didn't Kelvin Skerrett once do this into a fight? Seem to remember him gracefully flying over a brawl right into the middle swinging!

Our Kelvin did'nt do gracefull.

Eric Batten, Bradford Northern

Son of Billy, who taught him all he knew.

it certainly couldnt have been billy boston, cos hurdling was banned before billy was playing.

Nick Du Toit definitely did it (diving over the heads of the defenders, almost identical to the NFL player) in a Challenge Cup game at Workington Town (the one that was played at Workington Reds football ground).

Yes my Dad tells me there where two South Africans who came to play at that time. Van Rooyen and Van Heerden. I think it was Van Heerden who used to leap over players.

It would be classed as dangerous play today.