Curry drew the incident involving hooker Bongi Mbonambi to the attention of referee Ben O'Keeffe around the half-hour mark of the match at the Stade de France.

The alleged slur is not audible on the referee's link. South Africa had previously announced they were investigating the incident and rugby union's global governing body has confirmed it is looking into it as well.

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"World Rugby takes all allegations of discriminatory behaviour extremely seriously," a statement from the governing body read.

"We can confirm that we are formally reviewing the allegation made by England's Tom Curry's in relation to the use of discriminatory language during the England versus South Africa Rugby World Cup 2023 semi-final on Saturday.

"World Rugby will not be making further comment until the conclusion of the process."

When asked after the match if Mbonambi had said something he shouldn't have done, Curry replied "yeah", although he declined to reveal what was said.

Mbonambi refused to shake Curry's hand at the end of a dramatic clash in Paris that was won by Handre Pollard's penalty after 78 minutes.

England - who had until Monday morning to lodge an official complaint with the citing officer - have declined to make any comment on the incident.

If World Rugby's inquiry triggers disciplinary proceedings they are likely to fall under the banner of 'bringing the game into disrepute', which can result in a range of sanctions including a suspension and/or a fine.

No indication has been given of how long the investigation will take, complicating South Africa's build-up to the World Cup final, but it is understood there is a desire for it to be brought to a conclusion as soon as possible.

Apart from the disruption caused by the fallout from the incident, the Springboks face the possible scenario of entering Saturday's clash with New Zealand without a front-line hooker.

When Malcolm Marx was ruled out of the tournament by a knee injury in mid-September, fly-half Handre Pollard was called up instead of a replacement front row, leaving Mbonambi as the squad's only specialist in the position. Deon Fourie and Marco van Staden have been viewed as sufficient cover at hooker, but both players are primarily flankers.

A player cannot be called into a World Cup squad to cover for suspension, but special dispensation can be granted if it is felt the integrity of a match might be affected, in this instance by scrums having to be uncontested.

'Mbonambi is down to earth, a really humble guy'

South Africa scrum coach Daan Human:

"Mbonambi is a calm guy, actually, well spoken and I don't want to go into it because we've got a World Cup final in six days time and like I said, I'm more concentrated on the forwards.

"I can't comment because I wasn't on the field. I wasn't even aware of it [the incident]. He's down to earth, a really humble guy and he's a guy I would definitely have in our team.

"We've got three hookers in the group who are capable of playing in that position so at this moment we're glad we've got three hookers, which we're supposed to have."

'Mbonambi ban would leave Springboks in precarious situation'

Sky Sports News reporter James Cole:

"World Rugby are investigating this allegation made by England flanker Tom Curry. The incident happened 23 minutes into England's semi-final defeat to South Africa here in Paris on Saturday night. You hear on referee Ben O'Keeffe's microphone Curry saying to the referee that he's received a racial slur from South African hooker Bongi Mbonambi and questions what he should do.

"I understand there is no audible evidence to which confirms the allegation but Curry did say after the game that something untoward was said to him. World Rugby say they are taking the allegation extremely seriously, but will not be making any further comment.

"If Mbonambi were to be banned it would leave South Africa in a very precarious situation in terms of their hookers because he is the only specialised hooker left in the South African squad. Saturday's game was a physical contest and one that saw numerous flashpoints, including at the full-time whistle when South Africa full-back Willie Le Roux ran over to the England players to celebrate which escalated in a scuffle. Mbonambi did not shake hands with Tom Curry at the end of the game."

What's next?

The victory for South Africa means they now face New Zealand in a World Cup final at the Stade de France in Paris on Saturday October 28 (8pm kick-off BST).

The defeat for England means they come up against Argentina in next week's World Cup third-place play-off at the Stade de France in Paris on Friday October 27 (8pm kick-off BST).