Nobel Prize for literature winner Mo Yan has expressed hope that China's imprisoned Nobel Peace Prize winner Liu Xiaobo will regain his freedom.

Mr Mo told reporters today he hoped Liu could "regain his freedom very soon."

While stopping short of an outright call for Mr Liu's release, Mr Mo's remarks put a dent in the ruling Communist Party's attempts to use his historic win to burnish their credentials.

His statement also answers criticism from human rights activists who say he is compromising his artistic and intellectual independence by being a party member and vice president of the official writers association.

Mr Mo is the first Chinese citizen awarded the literature prize.

Mr Liu was sentenced to 11 years in prison in 2009 for co-authoring a call for ending single-party rule and enacting democratic reforms.

Meanwhile, an international rights group has released a video in which it says Mr Liu's wife is shown under house arrest.

Reporters Without Borders made the video public and called on authorities to release Mr Liu from house arrest and stop harassing his family.

In the video, a lone woman identified as Liu Xia is shown smoking by a window with its blinds open.

China in 2009 sentenced Mr Liu to 11 years in prison on charges of inciting subversion of state power.