SINGAPORE - Former minister of state for Defence Bernard Chen Tien Lap wrote a letter of condolence to Prime Minister Lee Hsien Loong even as he was ill himself, Mr Lee has said in a Facebook post.

"When my father died a fortnight ago, Bernard wrote to me. I was moved. Despite his illness, Bernard made the effort to console me, and to explain that he was unable to pay his personal respects to Mr Lee because he was terminally ill," Mr Lee wrote on Thursday night after visiting Mr Chen's wake to pay his respects.

Mr Chen died of cancer on Wednesday morning. He was 72. He was a People's Action Party MP from 1977 to 2001 and was active in the labour movement.

Mr Lee said he replied to Mr Chen to thank him, and shared that Mr Chen was supportive and gave him advice when he first entered politics.

"Bernard had definitely done more than his fair share and contributed much to Singapore. I counted it my privilege to have been his colleague and friend all these years," he said.

Mr Lee added that Mr Chen was a "grounded, hardworking and humble man" who contributed to Singapore in many roles. He had also been a civil servant in the Economic Development Board and Finance Ministry, as well as an MP for Radin Mas and West Coast GRC.