Cristiano Ronaldo may have violated health protocols by travelling to Portugal for international duty, according to Italy's minister for sport Vincenzo Spadafora.

The Juventus forward linked up with his national side for their October fixtures after the Serie A champions had created a 'bubble' at the team hotel, with two members of staff having tested positive for coronavirus.

According to reports from Italy, Ronaldo returned two negative COVID-19 tests but needed one more before being officially granted permission to leave fiduciary isolation and travel to his homeland.

He played a part in Portugal's goalless draws with Spain and France but was ruled out of Wednesday's win against Sweden after testing positive for the respiratory disease. 

Juventus confirmed on Wednesday that Ronaldo returned to Turin on a medical flight authorised by the competent health authorities.

Ronaldo was reportedly taken home in an ambulance to ensure no quarantine protocols were breached and is now undergoing a period of isolation.

However, while Juve say the five-time Ballon d'Or winner has acted within the rules, Spadafora disagrees.

Asked if Ronaldo's travelling violated coronavirus protocols, Italy's minister for sport told Rai Radio 1: "Yes, I think so. If there haven't been any specific authorisations from the health authority."