Joost van der Westhuizen showed signs of improvement on Sunday, according to the J9 Foundation.

'Joost has been much better today, however he is tired and been resting this afternoon,' the Foundation stated on its Facebook page.

Earlier in the day, the Foundation said: 'Joost remains in ICU in a critical but stable condition. He is responding well to his loved ones and putting up an incredible fight. He really is our Superman!'

The former Bok scrumhalf, who was diagnosed with motor neurone disease in 2011, was rushed to hospital on Saturday and said to be in a critical condition.

In an interview with the SABC, Hennie le Roux said his former Bok team-mate 'was being kept alive on machines' and that it 'doesn't look good for Joost'.