Beijing  - US President Barack Obama's half-brother has revealed at a book launch in China that his father used to beat him.

Mark Ndesandjo, from Obama's father's third marriage with a US woman, introduced his book From Nairobi to Shenzhen on Wednesday in southern China where he now lives, Chinese media reported.

The US president and Ndesandjo share a common father, Barack Obama Sr.

The revelation came shortly before Obama is due to make his first official visit to China.

Ndesandjo's semi-autobiographical novel concerns domestic violence and its effects on children.

He said that 15 per cent of the proceeds from the book would go to children's charities.

Ndesandjo was born in Kenya and studied in the US but is now married to a Chinese woman and lives in the economic boomtown of Shenzhen where he works as a business consultant.

Barack Obama is due to visit Shanghai and Beijing between November 15 and 18 as part of a trip to Asia. Ndesandjo plans to meet his half-brother in the Chinese capital. (dpa)