Chinese Christian human rights lawyer, Zhang Kai, has been seen for the first time since his arrest last year, appearing on a televised "confession" broadcast by a Chinese state-controlled channel.

Kai, 36, was arrested by security forces on 25 August 2015, hours before he was scheduled to meet with US ambassador for religious freedom.

In the television broadcast, Zhang admitted to crimes including endangering national security:

"I also warn those so-called human rights lawyers to take me as a warning and not collude with foreigners, take money from foreign organisations, or be engaged in activities that break the law or harm national security and interests," he said on the Wenzhou TV channel.

Kai provided legal advice for churches resisting the persecution they were suffering. He had represented more than 100 churches fighting orders to remove their crosses. He also wrote and distributed a 'Cross Activist Handbook' advising church leaders on how they can use China's own constitution, which guarantees religious freedom, to defend their rights.

He had been an outspoken critic of Chinese President Xi Jinping's human rights records. He was arrested in a church in Wenzhou, Zhejiang province and charged with "endangering state security" and "disturbing public order".

This television "confession" has been met with outrage by his supporters.

"It is utterly appalling for a person to be made to confess on television," said Zhang Lei, a fellow human rights lawyer. "[Televised confessions] go against basic human dignity and are also a violation of the law stating that people cannot be forced to confess."

Amnesty International's China researcher, William Nee, said he thought the confession was scripted.

"Once again, the Chinese authorities have flipped the truth on its head, confusing black and white," Nee said.

"It is not Zhang Kai's rights defence and exposure to the outside world about what is happening in China that hurt the reputation of the Chinese government: it's the Chinese government's violations of freedom of religion – tearing down crosses, destroying churches, throwing pastors into secret detention – that hurt its image."

Christian Solidarity Worldwide's chief executive, Mervyn Thomas, also criticised the move: "This alleged 'confession' by lawyer Zhang Kai is another concerning development in the ongoing crackdown against those who seek to peacefully uphold human rights and rule of law in China," he said.

More human right defenders have been detained or are missing under two years of President Xi Jinping's leadership than in the previous two decades. Many have worked on behalf of churches targeted by the demolition campaign.

Kai is among those held in 'black jail', with no legal status. Ahead of his first arrest, he allegedly told his friends: "I've made up my mind: the most they can do is jail me. But if I stay silent, I'll regret it my whole life."