Academic Huang Jing has resigned as an independent director of Keppel Land with immediate effect.

This comes after his permanent residency was cancelled last Friday, after he was found to be working with a foreign government to influence Singapore's foreign policy and public opinion here.

The Ministry of Home Affairs (MHA) had earlier announced that Dr Huang and his wife Shirley Yang Xiuping, who are United States citizens, would be permanently banned from Singapore, in what is the first publicly known case of its kind in nearly two decades. It said in a statement that Dr Huang has been identified as "an agent of influence of a foreign country" who worked with intelligence organisations and agents from that country. It did not name the country.

In an exchange filing released yesterday in the early hours of the morning, Keppel Corp said its subsidiary Keppel Land "has received and accepted Dr Huang's resignation as a director with immediate effect".

Dr Huang had been a member of Keppel Land's board since 2014.

The 60-year-old was also the director of the Centre on Asia and Globalisation and Lee Foundation Professor on US-China relations at the Lee Kuan Yew School of Public Policy, which is part of the National University of Singapore (NUS).

The NUS has suspended Dr Huang without pay while it works with the MHA.

An NUS spokesman has said that his employment was conditional on him having the necessary work permits.