BEIJING -- Two-time Olympic swimming champion Sun Yang has been suspended from training and competing indefinitely for repeated absences and being out of contact, his college said on Tuesday.

The announcement by Zhejiang College of Sports came a day after Sun was given seven days of administrative detention as punishment for driving without a license after his Porsche SUV was hit by a bus.

School vice-president Zhang Yadong said the decision to stop Sun from training, competing and participating in commercial activities was made before Sunday's collision.

"The car crash case simply forced us to announce this decision earlier than expected," he said by phone. "He has not been back to the school recently, and we could not reach him by phone."

Sun, the first Chinese man to win an Olympic swimming gold with his victories in the 400 and 1,500-meter freestyle at the London Games, apologized on Monday on his Twitter-like microblog for driving without a license.

The 21-year-old said he had been driving his relative's SUV when it was rear-ended by a bus on Sunday afternoon in his hometown, the eastern city of Hangzhou.

A product of China's strict state sports system, Sun was formally censured by his training school in February after feuding with his coach and missing practice in order to make commercial appearances and spend time with his air hostess girlfriend.

He was docked a month's stipend, suspended from commercial endorsements, and forced to make a public apology.

In late July, early August, he won three gold medals at the worlds in Barcelona.