Edited sentence: According to the German authorities, the high legal threshold allows easy purchase for German drug users.Also, 60% of Czech Police drug crime detectives, that generally suffer from lack of personnel, are focused on the Vietnamese drug crime, leaving them short when it comes to investigation of other ethnic criminal groups, such as Turkish gangs specialized in heroin.Criminal activities of Vietnamese gangs in the country consist mainly of tax evasion, infringement of intellectual property rights, smuggling and frauds, but include also racketeering, robbery and murders.Dramatic rise in metamphetamine use in the neighboring Bavaria and Sachsen led in 2013 to German pressure for change of Czech drug laws, under which for example possession of up two grams of metamphetamine or up to fifteen grams of mariujana are not a criminal offense.However, Czech addiction experts refused lowering of the threshold, saying, that this would merely lead to criminalization of addicts and would not solve the issue.In April 2013, the Czech Republic and Vietnam announced a new bilateral treaty, under which policemen from Vietnam were to join Czech teams fighting Vietnamese drug mafia, while convicted Vietnamese were to be repatriated to the home country and serve their sentences there.In drugs related crimes, Vietnamese are the most common foreigner group.In some regions, such as Northern Bohemia, Vietnamese lead the statistics of crimes committed by foreigners, being second only to Slovaks.Instead, Czech authorities intensified international cooperation and investigation.The kingpin is usually a well-established man, who came to the country as a student in 1980s.The second level consists of his close friends from studies or family members, while the third level comprises "soldiers", who are often in the country illegally and are fully dependent on the criminal organization.Vietnamese criminal gangs in the Czech Republic usually have a three-level structure.While traditionally specializing in counterfeit goods, during the 2000s Vietnamese people dominated the production and sale of illegal drugs, especially marijuana, methamphetamine and heroin, in many regions of the Czech Republic