Two Hong Kong booksellers 'back in China'

The five men were all linked to Causeway Books and the Mighty Current publishing house

Two Hong Kong booksellers caught up in a criminal investigation in China have returned to the mainland after a brief stay in the territory, a friend says.

Cheung Jiping and Lui Bo had been released from police custody in southern China last week.

But a close friend told the BBC they were in Hong Kong for only a few hours before going back to China as part of their bail conditions.

Both men have confessed to trading in illegal books in China.

Their supporters believe the confessions, made on Chinese TV, were forced.

Mighty Current publishing house disappearances

1. Lui Bo, general manager, goes missing in Shenzhen, 15 October

2. Cheung Jiping, business manager, 32, goes missing in Dongguan, 15 October

3. Gui Minhai, co-owner, 51, goes missing in Thailand, 17 October

4. Lam Wingkei, manager, 60, last seen in Hong Kong, 23 October

5. Lee Bo, shareholder, 65, goes missing in Hong Kong, 30 December

• Hong Kong bookseller Lee Bo says he will abandon UK residency

• Hong Kong's missing booksellers and 'banned' Xi Jinping book

• Missing booksellers paraded on Chinese TV

Mr Cheung and Mr Lui returned to Hong Kong separately last week. Hong Kong police say the men asked for the missing person cases filed on their behalf to be dropped.

But Hong Kong police did not say how long they stayed in the territory or where they are now.

Bei Ling, president of the activist group Independent Chinese PEN Center and a close friend of detained publisher Gui Minhai, told the BBC's Juliana Liu they had gone back to China after a few hours.

He said Mr Cheung had gone to his wife's family in Dongguan and Mr Lui to his family in Shenzhen, following their bail conditions. They could yet face trial.

Mr Cheung and Mr Lui are two of five men linked to a Hong Kong publishing house and book shop who went missing last year and resurfaced in police custody in China.

They had all dealt with books which were critical of Chinese leaders.

The case has sparked international concern that China could be attempting to rein in freedom of expression in Hong Kong, though China says its officials would not act illegally.

The fate and the locations of the three other booksellers remain unknown.