A steady increase in the number of freelance overseas sex workers in Hong Kong's male escort industry is making it one of the biggest sectors of its kind in Asia. That was the claim of Michael - not his real name - who contacted the Sunday Morning Post to highlight how the city's male escort business has soared in recent years. Michael, from northern Europe, is in his late 20s and has been based in Hong Kong for more than six years. He still uses a tourist visa as he spends up to five months a year working as a male escort in other Asian countries. Male escorts from Europe, South America and the mainland come to the city for two weeks at a time, before moving on to another country, Michael explained. They advertise their services through profiles on gay introduction and meeting websites, such as Gaydar and similar phone applications. These websites are international and based in Europe and the US, but with sections relating specifically to Hong Kong. Others advertise on the likes of Craigslist or in the local media. Michael said that about 90 per cent of clients looking for a male escort in Hong Kong were men. The rise in freelance expatriate escorts in the city has cut into Michael's earnings. Where once he could make HK$30,000 a month, he's sometimes now lucky to generate HK$19,000. 'There has been a big increase in male escorts from South America and the mainland,' he said. 'When I first came here in 2006, I could charge HK$5,000 an hour for my services, but not any more. That was when there were no Latinos in the market. 'Now my normal price is HK$2,000 for one hour, but South American escorts will charge less than that. I will have only three or four clients a week, while they will have many more. They have realised there's plenty of money to be made here and in other parts of Asia.' South American escorts came from the likes of Brazil, Colombia, Ecuador and Venezuela. Dr Travis Kong, a sociologist at the University of Hong Kong, said mainland sex workers - called 'Money Boys' - would come to Hong Kong for a short stay, due to visa restrictions, then go to Macau, Thailand, Malaysia and Singapore and return to the mainland. 'They form an interesting circle, what I call the 'circuit of desire',' he said. 'But they usually charge HK$500-700 or even less. Mainland sex workers contribute the largest portion of the Hong Kong male sex industry and they mainly use the internet and 3G apps for advertising.' Michael said that generally, expatriate escorts were used by expatriate customers and mainland escorts by local Chinese customers, although there was 'still some crossover'. Like mainland freelance escorts, expatriate escorts would also do a 'circuit' of Asian countries, starting off in Singapore and going from there to Kuala Lumpur, Bangkok, Hong Kong, Shanghai and Beijing - spending a few weeks in each country. Beforehand many would advertise the dates they would be travelling to each country on the internet to alert prospective customers. 'They'll make sure and have regular clients in each city to make sure their costs are covered. Anything extra is clear profit,' Michael said.