Chen Guangcheng, the Chinese activist, has spoken to US Congress for the second time accusing authorities in his country of persecuting his family.

Chen said that implication of his nephew in a murder case was politically motivated.

Earlier this month, the Chinese activist carried out a daring escape from house arrest and took refuge at the US embassy in the communist country's capital.

He wants to get his wife and two children out of China and move to the US to study, but still waiting for papers from authorities.

Al Jazeera's Nicole Johnston reports.