Kim Jin-Sun, who has led the committee since 2011, announced he was stepping down a year before his current term ends in October 2015.

He did not elaborate on the reasons, saying only that the committee needed new leadership at a “crucial time” with the Games in Pyeongchang a little more than three years away.

“Preparations for the Winter Games are now entering a final half, a transitional period that requires more meticulous administration,” Kim said in a statement.

“I thought the committee needed to strengthen its system under a brand new leadership,” he added.

Kim, 67, is a former governor of Gangwon province where Pyeongchang is located, and was the driving force behind the 2018 bid, having lost out in 2010 and 2014.

Recently, the organising committee has come under scrutiny over the pace of construction, after delays caused by controversy over the environmental impact of the Games.

It is also the subject of an ongoing probe by the state audit commission, reportedly connected to budget spending.

Kim stressed that his departure had “nothing to do” with the audit.

The government has undertaken to pump around nine trillion won ($8.8 billion) into infrastructure projects for Pyeongchang, a mountainous resort town 180 kilometres (110 miles) east of Seoul.