Former Deputy Prime Minister Wong Kan Seng has undergone surgery to remove a small lesion from his liver.
He is recovering and will be on medical leave for about two months, said a statement from his constituency office on Wednesday.
Mr Wong is an MP for Bishan-Toa Payoh GRC, and in his absence, the other MPs in the constituency will assist him in his constituency duties.
Mr Wong is currently chairman of Singbridge International, a wholly owned unit of Temasek Holdings, which primarily develops and invests in large-scale integrated townships in China.
He was Deputy Prime Minister from 2005 to 2011 and Home Affairs Minister from 1994 to 2010.