TAIPEI - Seventies movie sweetheart Chen Chen and legendary entertainer Liu Chia-chang have been divorced for more than 20 years, but kept up the pretence of being married to protect their son, she revealed on Wednesday.

The former actress' shocking admission to the Taiwanese press came after break-up rumours began in recent years, including a new story that her former husband is suing her in Hong Kong, said Apple Daily.

Responding to the lawsuit rumour, she said: "We are both so old, I hope there will be mutual respect."

Chen, 66, said she and Liu, 72, had decided to divorce in 1987, when their son, Jeremy, was one.

For more than two decades after that, they maintained the image of a happily married couple.

In 2007, he hosted a dinner to celebrate her 60th birthday in Hong Kong. In 2009, they appeared together when Jeremy was releasing a record in Taiwan. In 2010, when she underwent surgery for stomach cancer, Liu said he would not know how to live without her.

In fact, they have not lived together for decades and meet only for media appearances, said Apple Daily.

Chen said of the decades of pretence: "Because Jeremy was a child then, I wanted him to have a healthy environment to grow up in. Now my son is a grown-up, and Mr Liu also wants to sue me, I can't hide it any more."

Two years ago, when Next Magazine reported that the marriage was breaking up, Chen had considered announcing the split, she said. But there were too many rumours then - Liu was said to be fond of gambling, and spending too much time at his former wife's home - and she decided not to.

She refused to reveal the reason for the divorce, but said: "I hope everything ends here."

Chen had known Liu since she was 16, but she was too young then and her mother did not approve of the romance. Chen later married actor Patrick Tse. Chen and Liu married in the United States in 1978, after their previous marriages ended.