Liu Xiang (R) and Ge Tian. [File photo]

Retired Chinese star hurdler Liu Xiang and his wife have declined to respond to speculations that their marriage is in trouble or that they may have separated.

"The couple has great differences in personality and can't get along with each other," according to Entertainment Online, a program of Shanghai-based Dragon TV, citing an insider.

Liu, a Chinese Olympic gold medalist and world champion in the 110m hurdles, announced his retirement on May 17 at a stadium in Shanghai.

He did not mention his wife in speeches and she was not present at the event, giving rise to speculations that they had separated.

When asked about Liu's retirement, actress Ge said,"I wish him well, and I am certain he will be."

The couple is also not following each other via Chinese Twitter-like service Sina Weibo.

Liu and Ge were married last September, and Liu's post of the couple leaning on a hurdle with the caption "My beloveds, her and it" triggered more than 22 million responses and views within a few hours.

Calls to the pair have gone unanswered, Entertainment Online said.