Olympic champion swimmer Sun Yang has parted company with longtime coach Zhu Zhigen again, the Zhejiang College of Sports, with which they are affiliated, confirmed at a media briefing on Thursday.

Zhu, who has worked with Sun for more than 10 years, applied for a leave from the post for personal health reasons earlier this month and has stopped coaching Sun after receiving permission from the national swimming administration, the college said.

Zhang Yadong, assistant dean of the college and former coach of the national swimming team, will replace Zhu. Zhang briefly coached Sun during the FINA World Championships last year.

It was the second time Sun and Zhu separated. In February 2013, Sun first asked to change coaches because of a conflict with Zhu during a training session. But the two reconciled after mediation by the college after the World Championships.

During Zhu's absence last year, Zhang took over with Sun and helped him win three gold medals in the 400m, 800m and 1,500m freestyles in August.

"Sun is now training with me. I have nothing to say about the coach change. I just follow the arrangement of the administration," Zhang was quoted as saying on Thursday by ifeng.com.

Neither Sun nor Zhu made comments on Thursday.

Sun, who claimed gold medals in the 400m and 1,500m freestyle under Zhu's guidance at the 2012 London Olympics, resumed systematic training in March after being suspended by the college for driving without a license in November.