A former British consulate employee who was detained and allegedly tortured in China over Britain's role in Hong Kong anti-government protests has cut ties with his family to avoid them being harassed and threatened, the man has revealed.

Simon Cheng Man-kit's case triggered a diplomatic row between London and Beijing at a time when relations were already strained by the massive pro-democracy demonstrations that have wracked the former British colony for months.

'I hope they can live in tranquility and peace, without external harassment and threat,' the 29-year-old man said in a statement posted on his Facebook page Thursday night.

'What I do and say solely represents myself, it is not relevant to my family and relatives,' added Cheng, who worked at the consulate in Hong Kong until late 2019 and is currently in exile.

Simon Cheng, a Hong Kong citizen, told BBC that he was shackled to a steel 'tiger chair', hung spread-eagled on a 'steep X-Cross' and beaten while being detained by police in Shenzhen

Cheng was held for 15 days by mainland Chinese police who said he had solicited prostitutes

He did not elaborate on the 'harassment' and did not reply to requests for further comment.

In August last year Cheng, a Hong Kong citizen, disappeared while on a business trip to the neighbouring Chinese city of Shenzhen.

Cheng said he was tortured and interrogated by Chinese secret police while he was detained there for 15 days.

Chinese police released footage to show Cheng 'soliciting prostitutes and making confessions'

Mr Cheng, 29, claimed he had been tortured and accused of spying for Britain by Chinese police. He was detained in August after travelling from his hometown Hong Kong to Shenzhen

Police in Shenzhen said Cheng had been found guilty of soliciting prostitutes - allegation the man and his family have denied.

Chinese state media also released footage they claimed showed Cheng going to a 'club' and making confessions. Cheng said he got a massage for relaxation on the day he was reported missing.

Since leaving his job at the consulate, Cheng has lived in self-exile in Britain where he has been campaigning for democracy in Hong Kong.

In November, Cheng said during his time in detention he was shackled, beaten, forced to stand for long hours and deprived of sleep by Chinese secret police, who interrogated him about what role Britain played in the Hong Kong unrest.

Cheng said he was tortured by Chinese secret police, who interrogated him about what role Britain played in the Hong Kong unrest. In the picture above, thousands of protesters fill a street of Hong Kong to the brim during a pro-democracy demonstration on June 16 last year

The protests, which were triggered by a proposal to allow extraditions to mainland China, have morphed into a wider movement for democratic freedoms and against China's tightening control over Hong Kong. Pictured above, riot police guard a street of Hong Kong on January 1

Beijing and Hong Kong have accused 'foreign forces' of being behind the movement

The protests, which were triggered by a proposal to allow extraditions to mainland China, have morphed into a wider movement for democratic freedoms and against China's tightening control over Hong Kong.

Both the governments in Beijing and Hong Kong have accused 'foreign forces' of being behind the movement.

While he was in detention, Cheng said he was asked if he knew anyone who worked for British intelligence agencies, what part he had played in protests and what he knew about mainland citizens who had joined the demonstrations.

Beijing has faced criticism in the past for detaining foreign nationals amid ongoing diplomatic spats, and for accusing dissidents or activists of sex crimes.