Former South Africa scrum-half Joost van der Westhuizen is doing "much better" as he receives hospital treatment having been in a critical condition yesterday.

The 45-year-old has suffered from motor neurone disease since 2011 and was admitted to a hospital in Johannesburg on Saturday, where he was put in intensive care.

The World Cup winner's condition has since improved, though, with updates on Sunday saying that he is "putting up an incredible fight".

"Joost has been much better today however he is tired and been resting this afternoon. Thank you for the continued support for him and his family," read an update on the J9 Foundation's Facebook page.

Van der Westhuizen is widely regarded as one of the greatest scrum-halves of all time, having won 89 caps for South Africa between 1993 and 2003.