The J9 foundation has clarified Joost van der Westhuizen's use of oxygen as he continues his battle with motor neurone disease.

News emerged on Friday suggesting that Van der Westhuizen had been placed on oxygen, but the former Springbok scrumhalf then took to Twitter to deny this was the case.

His foundation, which seeks to help those suffering with motor neurone disease, has since issued a statement to clear up the matter.

'Joost is still fighting strong, he uses oxygen as a support occasionally and is by no means reliant on it. What happens with MND is that the respiratory muscles become weak [as do all muscles] and due to this, patients sometimes need oxygen support as the breaths are smaller, [and] thus less oxygen goes through the body.

'Oxygen support then just helps bring the levels up again when they feel they need it.'

Photo: YOU magazine