Liu Xiang to tie the knot on 'lucky' Sept 9, father says

(ECNS) -- Star hurdler Liu Xiang was said to be getting married to his mysterious girlfriend on Tuesday, an auspicious September 9, which symbolizes longevity of marriage.

The hurdler's father Liu Xuegen said Liu and his girlfriend will get registered on Tuesday.

One day before, on the Mid-Autumn Festival, a photo of Liu and a girl both holding a large bouquet of flowers at a marriage registration center in Shanghai's Putuo District was posted online.

It was not clear why the couple had gone to the center that day, although some netizens said it might have been in preparation.

The 31-year-old sports star has been in a stable relationship since 2012, the Xinmin Evening News said, citing his father a month ago.

The mysterious girl is not in the entertainment or sports circles, the father said.

However, an entertainment firm said online that the girl had worked for them as an actor. Rumors also said the girl and her father, a senior executive, are both from the aviation industry, thepaper.cn reported.

Liu posted a photo with the girl on his Sina Weibo account Tuesday.

Liu is one of China's most commercially successful athletes and has emerged as a cultural icon. He is the first Chinese athlete to achieve the "triple crown" of athletics: World Record Holder, World Champion and Olympic Champion.