Hill, 27, of Melbourne, was put in a medically-induced coma and taken from Beijing by Medivac aircraft to a specialist hospital in Hong Kong last night.

He was suffering pneumonia after falling ill with heat stress while working for the Macquarie Network.

Mike Tankred, media director of the Australia Olympic Committee, which helped organise Hill's evacuation, said the broadcaster's condition had improved in Hong Kong's Adventist Hospital.

"His breathing has improved, his organs are improving and they are still running tests to try to determine what bug he picked up," Mr Tankred said.

"He is breathing 50 per cent oxygen, the doctor said, apparently you and I breathe 25 per cent oxygen, so he is still getting assistance with his breathing, but his breathing has improved."

Mr Tankred was unaware whether Hill remained in a coma.

Family members have flown to Hong Kong to be by Hill's side.

A spokeswoman for Radio 2GB said the station was yet to hear from relatives today.