A prominent pro-democracy activist has fled Hong Kong to seek asylum in the UK, breaching a supervision order.

Tony Chung, 22, told the BBC he had been under constant scrutiny in Hong Kong, where police had put him under an "enormous amount of stress".

He also claimed he had felt compelled by police to become a paid informant, giving information on fellow activists.

Chung was convicted of calling for Hong Kong's secession under a tough security law. He finished his sentence in June.

But upon his release, he says he was thrown into a situation that was "an even bigger and more dangerous prison" than the one he had left.