'I felt as if the world was crumbling around me,' Mr Mpofu said from South Africa yesterday. 'I was humiliated and stripped of my human dignity for no reason. I was going to seek work to look after my wife and baby and I have lost everything.

'I was amazed at what happened to me, and I wouldn't rule out racism because most of the people I saw being detained in Hong Kong at the same time as me were black.'

Mr Mpofu, who has a wife and baby daughter in South Africa, insisted his passport was genuine and said he was considering legal action to seek compensation for his lost air ticket and job opportunity.

His case has been featured in South Africa's biggest daily newspaper, The Star, and has been taken up by the South African consulate in Hong Kong, which said the treatment of Mr Mpofu was part of a wider problem.

South African political consul Primrose Zwedala said the department should have contacted the consulate to check whether Mr Mpofu's documents were genuine or not.

'Under normal circumstances, if immigration officers believe there is something wrong with someone's travel documents, they call us at the consulate and fax copies of the passport to us to verify, but they didn't do it,' she said. 'We have been trying urgently to find out more about this case and the Immigration Department has agreed to meet us to discuss the situation on Monday.'

Ms Zwedala said of Mr Mpofu's case: 'This is a part of a general problem. There are other cases of black people being treated the same way in Hong Kong. We even get harassed, even ourselves as diplomats.'

She said she knew of a number of other cases in which people arriving from Africa had been subjected to strip searches, including a 32-year-old female relative who visited last year. 'When she arrived, she was crying. Her eyes were red. She told me they did exactly the same thing [as in Mr Mpofu's case] to her.

'In South Africa we stop people and check their documents sometimes but we don't treat people the way this gentleman was treated. Now he has lost his ticket and his savings. Who is going to pay for that?'

An Immigration Department source denied that Mr Mpofu had been strip-searched, saying he had been subjected to a normal routine search. He was referred to immigration at the request of Cathay Pacific staff who said he did not have a visa to enter New Zealand, the source said.

'Later ... when we looked at his passport, we found that his passport picture didn't look like him,' the source added.

However, South African nationals can enter New Zealand without a visa for up to three months, according to the New Zealand government's website. Mr Mpofu said he had appointments with job agents in New Zealand and would have applied for a work permit once in the country.

An immigration spokeswoman said the department 'has been authorised by law to conduct searches ... We fully respect the dignity and privacy of persons being searched.'

She added: 'Any foreigners who are detained are allowed to contact their consulate general.'

Asked about the specific details of Mr Mpofu's case, she said: 'We do not comment on individual cases.'