“I still desperately wanted to play this season, but in the end, decided to rather stop now. From now on, I’ll just sit and watch,” the 33-year-old told Afrikaans daily newspaper, Beeld.

“It would have taken me between eight months and two years to recover. Another option would have been an operation, but they are not always successful.”

Leeds rugby director Phil Davies added: “I am bitterly disappointed for Japie that his career has had to end because of an injury off the field.

“During his career, he won every honour available, and his record will mark him out as one of the world’s best. He was a credit to the club during his stay with us last season, and we wish him the very best in his life outside of rugby.”

Mulder burst onto the South African rugby scene as part of the all-conquering Transvaal team of 1993 that won the inaugural Super 10 competition, as well as the Bankfin Currie Cup.

Under the captaincy of Francois Pienaar, Mulder quickly built a reputation as one of the most feared defenders in the game.

He made his Test debut against the All Blacks in 1994 and he went on to secure 34 caps, scoring six tries for his country.

When he joined Leeds, Mulder originally agreed a dual-code contract to play rugby union and league. However, the neck injury meant that he was never able to take up the rugby league element of his contract.