A worker at the UK consulate in Hong Kong has been released by mainland China after being held at the border, a statement on his Facebook page says.
Simon Cheng went missing on 8 August during a business trip to Shenzhen.
China's foreign ministry confirmed that Mr Cheng had been detained for 15 days for violating public security laws. The UK had said it was "extremely concerned" by his detention.
It comes as anti-government protests in Hong Kong enter their third month.
The large-scale demonstrations were sparked by a now-suspended extradition bill that would have allowed Hong Kong to send criminal suspects to China for trial.
In a Facebook post, Simon Cheng said he "thanks you everyone for your support".
"Simon and his family wish to have some time to rest and recover," he added. " We will explain more later."
Who is Simon Cheng?
Mr Cheng, 28, is a trade and investment officer at the Scottish Development International section of the consulate, reports local outlet HKFP.
The report says Mr Cheng studied in Taiwan and the UK before returning to Hong Kong.
Mr Cheng travelled to a business event in Shenzhen on 8 August via the Lo Wu crossing.
His girlfriend said he planned to travel home by train the same day but did not return. In messages to his girlfriend, he wrote that he was passing through the border, adding "pray for me".
How did other countries respond?
Canada announced that it had banned staff from travelling outside the city, including to mainland China.
Global Affairs said in a statement to the BBC that local staff "will not undertake official business travel outside of Hong Kong".
However Canadian diplomats attached to the consulate will still be able to travel.
The Canadian government also updated its travel advice for China, warning of border checks on phones.
The advisory said: "Increased screening of travellers' digital devices has been reported at border crossings between mainland China and Hong Kong."
What is the situation in Hong Kong?
The protests were sparked by a now-suspended extradition bill that would have allowed Hong Kong to send criminal suspects to China for trial.
They have grown into a broader movement calling for democratic reform in Hong Kong, and an investigation into alleged police brutality against protesters.
Last Sunday, about 1.7 million people attended a pro-democracy rally in central Hong Kong, according to organisers. However police put the figure much lower at 128,000, counting only those at an officially sanctioned rally in the city's Victoria Park.
There have been previous protests at Hong Kong International Airport as well as tourist spots in the city.
On Friday, YouTube announced it had shut down over 200 channels that it said were part of a "coordinated" attempt to post material about the ongoing protests in Hong Kong.
Facebook and Twitter announced on Monday that they had taken steps to block what they described as a state-backed Chinese misinformation campaign on social networks.
Twitter said it removed 936 accounts it said were being used to "sow political discord in Hong Kong".
