Liu Xia, the widow of Nobel Prize laureate Liu Xiaobo, has been allowed to leave China for medical treatment in Germany.

The release comes amid speculation that her departure may have been linked to high-level diplomatic meetings.

“Liu Xia went to Germany for medical treatment according to her own will. It is no connections with the current important leaders visiting,” Foreign Ministry spokeswoman Hua Chunying said on Tuesday.

Liu Xia, 57, is currently en route to Berlin after spending the past eight years in China under house arrest.

Liu Xia, pictured in July 2017, has been allowed to seek treatment in Germany after eight years of house arrest. Photo: AAP

It comes the day after Chinese Premier Li Keqiang met German Chancellor Angela Merkel in Berlin for high-level trade talks.

Germany has previously said it would welcome Liu Xia, who has expressed a desire to leave China following her husband’s death at age 61 almost exactly a year ago.

Liu Xia has been living under house arrest and constant surveillance since her husband became the first Chinese citizen to win the Nobel Peace Prize in 2010. She has never been charged with a crime.

In recent months, friends and human rights organisations have expressed concern for her mental health.

Liu Xiaobo died on July 13, 2017 from advanced liver cancer, just weeks after he was released from serving an 11-year prison sentence for co-organising a pro-democracy manifesto for China in 2008.

A 2014 march in Hong Kong highlights the plight of Nobel Peace Prize winner Liu Xiaobo and Liu Xia. Photo: Getty

-AAP