The 38-year-old Austrian had a stent inserted in March after doctors discovered he had a narrow coronary artery which needed to be kept open.

He has now been cleared to return to high-level sport by Professor Josef Niebauer, a cardiologist who works at the University of Salzburg.

"I had speculated a bit that I wouldn't get the green light, since top-class sport is a very sensitive topic after a stent implantation," said Gruber, who won team Olympic gold at Vancouver 2010.

"However, the doctors agreed that I was 100 per cent fit again and this is my biggest win so far.

"I am really happy that I can continue to pursue my great passion, Nordic combined. 

"The way back will be anything but easy, I haven't done a single jump, no strength training and almost no fast training sessions. 

"A lot will go on in my head, but we have eliminated all ambiguities with the investigations. 

"I will always complete the training in close coordination with the doctors and undergo ongoing medical checks. 

"The way back is going to be a really difficult task but challenge accepted."

Gruber also has three Olympic bronze medals in his collection as well as a hat-trick of world titles.

"His values and performance are almost as good as they were a year ago when he was with us for the sports medical examination the last time," said Niebauer. 

"Even with extensive diagnostics, we could not find any abnormalities that speak against stress at the high performance level. 

"Bernhard is aware that with his medical history he has a higher risk of progression of coronary heart disease and thus also of corresponding events. 

"However, based on the currently good test results, nothing stands in the way of continuing his career for the time being."