South Korean police raided the headquarters of a state housing development corporation amid land speculation allegations involving more than a dozen of its employees.

The Gyeonggi Nambu Provincial Police Agency on Tuesday sent investigators to the head office of the Korea Land and Housing Corporation(LH) in Jinju, South Gyeongsang Province, to obtain relevant evidence.

Similar searches began at company offices in Gwacheon, Gyeonggi Province, and Incheon, as well as the residences of 13 employees implicated in the case.

The police have issued travel bans and also launched an investigation into the employees on charges of violating the anti-corruption law.

Two additional former employees are also under police investigation but they were not included in Tuesday's raid.

Last week, two civic groups raised allegations that current and former LH employees used confidential information to illicitly purchase land in two cities in Gyeonggi Province before the government announced a massive development project in the area.