Three-time Formula One champion Niki Lauda continues to recover in intensive care having had lung transplant surgery.

The Austrian woke up from a medically-induced coma on Saturday, two days after undergoing life-saving surgery at AKH Vienna hospital, it was revealed by FOX Sports.

Lauda flew to an Austrian hospital for treatment after he had fallen ill on holiday in Ibiza during mid-July.

However, his condition turned into severe pneumonia, which meant Lauda had to be connected to a heart-lung machine to supply his blood with the oxygen.

“The doctors decided that only a lung transplant can save the life of the Austrian national hero,” reported OE24.

Doctors determined Lauda would only survive for “three to seven” days without a transplant, as it became clear the situation was urgent.

FOX Sports reported a donor was found in Hamburg, Germany on Wednesday evening, and Lauda underwent surgery on Thursday, with a team of 10 specialists spending six hours performing the transplant surgery.

AKH’s head of thoracic surgery Professor Walter Klepetko, who led the surgeon in Lauda’s operation, said they are “very satisfied” with the 69-year-old's condition.

“He will be the old man again, he will be able to fly again, even work as before,” he told OE24.

In 1976, Lauda was involved in a huge crash as he went into an embankment at the Nurburgring circuit in Germany.

As flames surrounded his car, Lauda was rescued by his fellow drivers and suffered severe burns.

Despite this incident, Professor Klepetko said it was not a reason for his current condition.

“One can absolutely assume that lung transplantation is not a late consequence of the fire accident,” he told ORF.

Klepeteko predicted Lauda will spend four more weeks in hospital, but could make a potential return to his F1 work by early October.

Mercedes F1 team boss Toto Wolff said in a statement: “Although we should enjoy the start of our summer holidays this evening, none of us at Mercedes will pretend that we feel happy — our thoughts are rather with Niki, Birgit and the Lauda family.

“The world knows Niki as an F1 legend with incredible power and resilience. For all of us at Mercedes he is our chairman, our mentor and our friend. We have missed him by our side in Hockenheim and Hungary, and can’t wait to have him back with us.

“The recovery he faces is not a race. But I’m sure he will soon be telling every nurse and doctor that he has had enough of hospital.

“We wish him a safe and speedy recovery — in that order — and send all our positive energy to him and his family. I miss you my friend.”