Nearly half of the North Korean spies arrested by South Korean authorities in the past decade posed as defectors, a South Korean lawmaker citing data from the Ministry of Justice said on Friday.

Rep. Sim Jae-kwon of the opposition center-left Democratic Party said that according to the data, 49 North Korean spies had been caught south of the border in the last decade.

14 were arrested during the 2003-2008 Roh Moo-hyun administration, 31 under the 2008-2013 Lee Myung-bak government, and 4 under the 2013 – present Park Geun-Hye administration. Of the 49 arrested, 21 entered South Korea disguised as North Korean defectors.

Sim said