What if your real property in China is sold by an unauthorized person?

It happens not only in China. There seem to be property scam all over the world, click here and here.

A recent case intrigues me a lot.

Facts: an old Shanghai lady who become an American citizen back in 1990s left her apartment in down town area of Shanghai to her niece for use and care. Recently when she came back to Shanghai, she found that her apartment was now owned…