The Chinese secret police were polite when they telephoned to warn a man known as “A”.

They warned the former Chinese resident “not to go overboard” in his criticism of their government or its policies now that he has left the country.

But “A”, who lives in self-imposed exile in Japan, is more fearful when he hears that they visited his parents in Beijing.

“There have been times that they go to my parents’ home and ask about me, intimidating my family.” he told The Telegraph. “I am very worried that they could harm my parents or other people in my family”.

“A” is a 52-year-old former academic who became involved in human rights activities in China until he attracted the attention of authorities.

The dissident is keen to keep a low profile and does not want his name to be published, but says he remains committed to achieving freedom and democracy in his homeland.

His determination comes in spite of ongoing threats and intimidation from the ruling Communist Party, which do not stop even for Chinese expats that have fled the repression.