as tutors. In 2007 over 1800 foreigners on D-2 visas were found to be working illegally. Foreigners who have a D-2 visa are prohibited from working full-time. 2009 saw concern raised over Chinese nationals who overstayed their visas. There was an 11.7 times increase in overstays on the D-2 and other visas. It was also reported that "a number" of those entering on D-2 visas from China were doing so only to find a job illegally. In 2010, 68 illegal tutors on D-2 visas were caught by the immigration department. Corporate Investment (D-8) visa The Corporate Investment (D-8) visa is issued to foreigners who are going to own and manage a small or medium business in South Korea or who are sent as specialists to work at businesses owned by companies outside Korea. Individuals wishing to apply for this visa on their own must invest a minimum of 50 million won. The amount of money required as an investment by foreigners to obtain the visa has risen over the years. In 1991 a foreign investor was required to invest only 25 million won, then in 2001 this was raised to 50 million won. In 2010 the government announced that it was looking to increase this further to 100 million for a number of reasons. Due to inflation, a rise in the cost of living and other costs they felt that 100 million was more representative of what was required as a minimum investment to start a business in Korea. However, there was also concern that some foreigners were taking advantage of the visa and using it to reside permanently in Korea without actually creating any business. Once the visa has been issued the government doesn't keep track of the investment, so some foreigners were using agents who provided the investment money for a fee in order for them to obtain the visa. Concern was raised that the increase would do nothing to deter abuse of the visa and would instead discourage foreign investment in Korea. The regulations surrounding the visa and foreign business ownership have been criticized for requiring a Korean guarantor even though the foreigner has invested a large sum of money and been given permission to open nearly any business they wish. Foreign Language teaching (E-2) visa The Foreign Language teaching (E-2) visa is issued to foreign language teachers who work in South Korea. Applicants are required to