China's star swimmer Sun Yang will again train with coach Zhu Zhigen, who successfully worked with him for almost a decade, the Beijing Youth Daily reported on Thursday.

Zhang Yadong, Sun's interim coach, who led Sun to a hat-trick of world titles in Barcelona last month, the men's 1,500m, 800m and 400m freestyle, said he has finished his last training session with Sun and the swimmer will start training with Zhu again soon.

Sun stopped training with Zhu, because of an estrangement that has lasted for almost half a year.

Sun first asked to change coach due to a conflict with Zhu during a training session in February. But the two sides were reconciled after mediation by the Zhejiang College of Sports.

However, another flare up between them turned physical ending the relationship. Sun was left behind in Hangzhou when Zhu led other swimmers to train in Kunming, Yunnan province, for the World Championships

But according to the report, Zhu said that he has held a good talk with Sun and they have cleared the air.

Although he competed at the World Championships under the helm of Zhang, Sun expressed his gratitude to Zhu after winning the 800m race, saying Zhu "greatly enhanced my ability with aerobic exercises".

Zhu praised Sun's performance in Barcelona and said, "I told him that sunshine always comes after the rain and my door will be always open to him."

Shang Xiutang, deputy head of the swimming administrative center of the State sports authority, said Zhu is the proper coach for Sun and the sports governing body will be happy to see them working together again.

"But we haven't received any information yet from Zhejiang that Sun has returned to coach Zhu's group," said Shang.