By Brenden Nel

Carl Spannenberg, South Africa's most controversial referee, will officiate the crucial Super 12 game between the Bulls and the Cats on Friday night.

Spannenberg, who made headlines at the weekend after being accused of sexual assault on a player and who allegedly spent a night in jail on a charge of driving under the influence, will take charge of the Ellis Park pressure cooker after flying into a stormon Monday.

The South African Rugby Football Union (Sarfu) are investigating the allegations which were made in two separate weekend papers. They have, however, declined to take any action yet, leaving Spannenberg to referee one of the most important games in South Africa's rugby history.

The Cats need to beat the Bulls with a bonus point to stand a chance of a home semifinal place while the Bulls will be looking for vital points to avoid finishing as the joint worst Bulls side in the competition's history.

Spannenberg, who refereed Saturday's game between the ACT Brumbies and the Blues in Auckland, was appointed alongside touch judges Mark Lawrence and Andy Turner for the match. He was involved in another controversy in New Zealand when he sin-binned Blues centre Rua Tipoki for swearing at him.

According to reports, the accusation of sexual assault comes from a Griquas player after the side's loss to the Blue Bulls in a Vodacom Cup game in April. It's alleged he invited the player to his room and was allegedly not fully clothed when the player arrived.

Spannenberg has vehemently denied the report, saying it was "a blatant lie. It's rubbish".

But he'll have to appear in a Parow court on May 15 on the charge of driving under the influence and will still have to face any action decided by Sarfu.