SINGAPORE - Philanthropist Lee Seng Gee was a "rare, selfless and humble" man who contributed to Singapore his whole life, Prime Minister Lee Hsien Loong has said in a letter of condolence to Mr Lee's widow, Mrs Della Lee.

Mr Lee Seng Gee died at his home at age 95 on Tuesday (May 10), with his wife Della at his side.

"There have been many successful businessman in Singapore. But very few are like Mr Lee Seng Gee, who was even more successful as a philanthropist," said PM Lee in the letter on Wednesday (May 11).

"He was a rare, selfless and humble individual who contributed to Singapore throughout his life."

The Lee Foundation, which was chaired by Mr Lee Seng Gee, donated close to $1 billion to many good causes.

In the letter, PM Lee listed the Foundation's many charitable contributions to educational institutions, including those to the new National Library, the Nanyang Academy of Fine Arts, the Lee Kong Chian Natural History Museum and more.

The Foundation has also supported many volunteer organisations for social services and special needs children.

"Collectively, these efforts have enabled us to build a caring and compassionate society in Singapore," he wrote.

He also said that the late Mr Lee was continuing his father Mr Lee Kong Chian's "tradition of giving".

"His life reminds us that success is not defined by the wealth you amass, but by your contributions to the community," the Prime Minister wrote.

"Our thoughts are with you and your family during this time of grief."