A half brother of US president-elect Barack Obama appeared at a charity concert on Friday in the southern Chinese boomtown of Shenzhen where he played the piano to raise money for orphans.

Publicity for the event didn't mention pianist Mark Ndesandjo's family connections.

But the 200 or more people who showed up for the fundraiser at a posh hotel resort knew the performer was Obama's media-shy, intensely private half brother.

They had a rare encounter with the man who has been dodging the media ever since his family ties were made public last summer.

Ndesandjo has been living in China for 7 years and worked as a strategic marketing consultant. He also helped start a western chain of eateries in China.