China's artist Ai Weiwei releases single

Dissident Chinese artist Ai Weiwei has released a music single.

He said he became interested in music during his 81 days in detention without charge in 2011.

After he was released, he was accused of tax evasion and the authorities imposed 15m yuan ($2.4m; £1.6m) fine.

Ai, 55, says the charges are politically motivated.

Martin Patience reports.