Wera Hobhouse claimed she was the first British MP to be refused entry on arrival in Hong Kong since the former British colony was handed over to China in 1997.

Hobhouse is a member of the Inter-Parliamentary Alliance on China, a group that has challenged Beijing's human rights record.

Upon landing in Hong Kong on Thursday, Hobhouse had her passport confiscated, was asked about her job and the purpose of her visit, had her luggage searched and was then taken to the boarding gate, according to the Sunday Times newspaper.

Hong Kong defended its policy on Monday, with a government spokesperson saying "it is the duty of (an) immigration officer to ask questions to ascertain that there is no doubt about the purpose of any visit".

"It will be unhelpful to the person's case if the person refuses to answer questions put to him or her for that purpose," the spokesperson said, without commenting on the details of Hobhouse's case.

The incident was followed by a meeting Monday between British trade minister Douglas Alexander and Chief Secretary Eric Chan, the Chinese finance hub's number two official.

Alexander, who is visiting Hong Kong and mainland China, raised concerns and demanded explanations with "senior Chinese and Hong Kong interlocutors", the UK government said in a statement.

In a social media post, Hobhouse said "authorities gave me no explanation for this cruel and upsetting blow", adding that her son was waiting for her in arrivals.

Britain has criticised Hong Kong for clamping down on dissent and curtailing rights after the city saw huge and often violent pro-democracy protests in 2019.

Foreign Secretary David Lammy on Sunday said it would be "unacceptable for an MP to be denied entry for simply expressing their views as a parliamentarian".