SEOUL (AFP) - South Korea's German-born tourism chief on Friday announced his resignation after allegations emerged that he visited a lewd massage parlour in Japan last year.

Charm Lee dismissed the allegations as groundless but he found it impossible to carry on as CEO of the state Korea Tourism Organisation in its aftermath.

"It is regrettable that news media unilaterally repeated a groundless allegation" by an informant, Lee said in a press statement.

He said he wanted to restore his honour through a lawsuit.

Lee made the announcement three days after a local TV station reported that in 2012 he had visited a "soapland" massage parlour in Yoshiwara, a red-light district in Tokyo.

Lee, whose German name is Bernhard Quandt, became a South Korean citizen in 1986.

He landed the post in 2009 under the government of then president Lee Myung Bak, becoming the first naturalised Korean to ever lead a state organisation.

Charm Lee helped him in the 2007 presidential election campaign.