Mrs Pamela Mboya, the widow of former Cabinet minister Tom Mboya, has died after an illness.
Mrs Mboya died in a South African hospital while undergoing treatment.
The last time Mrs Mboya spoke in public was last February when she broke her silence following the assassination of her husband in Nairobi 40 years ago.
Mr Mboya, then the Economic Planning and Development minister, was gunned down on July 5, 1969 as he left a pharmacy on Nairobi’s Moi Avenue.
A man identified as Nahashon Njenga was later arrested and charged with the murder although the mystery of the killing has never been resolved.
Last year, Mrs Mboya wrote to the Kofi Annan mediation team and offered to shed more light on the unresolved case.
At the time, she said, she was willing to meet the former UN secretary-general in private to discuss the case.
At one time, Mrs Mboya served as the head of the UN Habitat.
She was born in Maseno, Siaya District. She got married to Mr Mboya in 1962 and together they had six children.