The room has pink wallpaper dotted with cartoon characters. On a bed covered with the kind of soft, fluffy duvet more often found in a young girl's bedroom, sits the forlorn figure of Ye Mexia. Her black hair is tied with pink ribbons and she is dressed in woollen tights, shorts and the kind of soft jacket often worn by young girls. It is hard to guess her age because she is heavily made-up to hide her fatigue. Her clothes indicate she could be nine or 10, but in fact she is in her 20s. Ms Ye, who says she is from Shanghai, is the human face of people trafficking that was exposed a few weeks ago after a bust by Spanish police of a brothel racket in the Leganes area of Madrid. One of 19 mainland women arrested in a major operation in Spain in recent months, Ms Ye told investigators that she was forced to work in cramped conditions and cater for men fantasising about having sex with children. Police who busted the prostitution rackets said they were being run by triad bosses in Spain who were making about Euro14 million (HK$145 million) a year out of the sex trade. A specialised police unit arrested the 14 leaders of six gangs who were running about 100 mainland women in a tightly controlled series of brothels across the country. They kept one step ahead of the police for months by changing the brothels every few weeks, sometimes working in hotels or operating a 'home delivery' service where girls would visit clients' homes. Although only 19 of the women were detained by authorities on immigration charges, they all had one thing in common: they were sex slaves, 'owned' by the gangs and working to repay the price of a ticket to the west from the mainland. It is a picture that appears to be repeated across Europe, where police investigators say mainland women are lured into the sex trade by people smugglers promising them a way out of poverty. Police forces, aid groups and academics across Europe agree that mainland women are playing a bigger role in the sex trade throughout western Europe. David Tattershall, an intelligence officer with the UK Human Trafficking Centre, said: 'We don't know how many Chinese people are being trafficked each year. Traditionally, they were eastern European girls, but now more and more Chinese women are becoming involved. There are no reliable figures on the number of Chinese women yet, but anecdotal evidence suggests this.' He said many mainland women typically worked in brothels to pay off their debt to people smugglers - one as high as HK$306,000. Ms Ye refused to talk about how she ended up working in a shabby Madrid brothel, most likely because of the shame it would bring her family. 'She is like a lot of the other girls we deal with - worried in case the gangs take it out on her family back home. It's always the same,' a Spanish police officer said. Police in Spain say more brothels are being operated by triad gangs as the Chinese population there swells. Official figures put the number of mainlanders in Spain at 90,000, although there are thought to be double the number working in the country's 'black economy'. Human trafficking was one of the triads' core businesses, said a source from the Unit Against Organised Crime, a specialised police squad in Spain. The most prominent triad gangs came from Beijing and Shanghai, he said. 'They are more subtle than Russian or Albanian-Kosovan gangs in Spain as they avoid using extreme violence because they know it will only attract our attention and is bad for business,' he said. Women like Ms Ye usually get just a fraction of the money they are paid for their services - the rest goes towards paying off their 'debt'. One problem police have in cracking the triads running the prostitution rackets in Spain is the language barrier. Lurid photos advertising Ms Ye's charms were published by her bosses in Chinese-language publications, making it hard for the Spanish police, with limited resources and few interpreters, to crack the well-organised outfits. But investigators said they got their break when a neighbour living next to one of the brothels claimed children were being abused. When police arrived they thought Ms Ye and the other women were under-age until they checked their passports and found they were aged between 24 and 29. A source from the Spanish police's foreigners unit said: 'We think they were forced to sleep with up to 60 men a day. Some would take medication so that they would not menstruate and could work more.' Most of the women were sending the cash home to their families on the mainland, not revealing how it was made. The triad bosses sent much larger amounts to loved ones on the mainland: at the home of one gang boss, police discovered Euro290,000 in cash. The emerging trend of mainland women being trafficked into Europe to work in prostitution has also been noticed by law enforcement agencies in Britain, where a special unit was recently set up to combat human trafficking and the law changed to establish it as a crime. Mr Tattershall of the UK Human Trafficking Centre said that in Britain and in other countries there was a genuine fear factor for these women, which makes them virtual prisoners of the brothel owners. 'But there are probably many women out there who have no idea we could help them get out of this situation,' he said. Last year, the Metropolitan Police in London launched a major operation against a gang trafficking Malaysian-Chinese women who were forced to work as prostitutes. Seven members of the Chinese gang lived in luxury flats in one of the most exclusive areas of London and drove Mercedes cars. They ran a number of prostitutes in brothels in London and Birmingham. But after a sophisticated surveillance operation, they were arrested and later pleaded guilty to trafficking and prostitution offences. 'There are those who believe they are coming over here to do a proper job and get sold at the airport,' said Carlo Narboni of the Met Police's clubs and vice unit. 'Others are forced to pay off 'debts' for their journey which are much higher than they thought. Others are still happy to make some money because it is much more than they would make at home.' The Scotland Yard vice squad works closely with the police Chinatown unit as London is home to the largest Chinese community in Britain. Across the Channel in France, a steady change appears to be taking place. After the second world war a large number of Chinese from Wenzhou emigrated to France, setting up businesses, running restaurants and becoming wealthy as they integrated into French society. But in recent years, French law enforcers say a new wave of immigrants have arrived from the mainland, desperate for a slice of a better life in the west. Marie Debrus, of the charity Medecins du Monde, said many failed to get to residency status and could not work legally. Many women were eventually forced to work the streets. Ms Debrus works in a pioneering project in Paris offering health advice to mainland prostitutes in an effort to help what is an isolated part of society. She says some of the women speak little or no French, most are aged between 40 and 50, and their main trade is with the Chinese community. 'They do not want their families in China to know what they are doing as it is a grave dishonour,' Ms Debrus said. 'Things are very difficult for them. Some believe they will go home eventually, but in reality they will not. Others want to stay. We offer them help because no one else was doing so.' Although estimates about the number of Chinese people who are the victims of the trafficking gangs are sketchy, reports from the US State Department confirm the problem of mainland women trafficked to France to work in the sex trade was on the increase. 'The government estimates that there are 10,000 to 12,000 trafficking victims in France, 3,000-8,000 of whom are children forced into prostitution and labour,' a 2004 State Department Report said. Another report last year by the same agency said there was a growing trend of children arriving in Europe from the mainland unaccompanied, possibly as part of smuggling gangs. 'Since 2004, 120 Chinese children have reportedly disappeared from Swedish immigration centres,' the 2006 report said. 'In all cases, the children arrived in Sweden on a plane from Beijing or Moscow and immediately asked for political asylum. Within days they had disappeared while their cases were pending. 'Investigative leads indicate onward destinations included Denmark, Germany, Italy, France, and the Netherlands. Swedish law enforcement authorities believe a network of traffickers is behind the disappearance. Several reliable non-governmental organisations have noticed a mysterious trend of unaccompanied mainland minors arriving in Europe with mobile phones, cash and no apparent travel plans, who then suddenly disappear from authorities and reception centres,' the 2006 report said. 'It is possible that these [children] disappeared when they came into contact with criminal networks.'