ZAMBIA’S ex-president Kenneth Kaunda was on Saturday hospitalised for an undisclosed ailment, forcing a requiem mass for his late wife to be cancelled, an official said.

"The family members have decided that the church service be postponed due to Kenneth Kaunda's sudden illness. Dr Kaunda has... been hospitalised at the University Teaching Hospital," said secretary to the cabinet Roland Msiska in a statement.

Kaunda's wife, Betty, died on Wednesday aged 83 in Zimbabwe where she was visiting her daughter.

Officials said she died in her sleep at the home of daughter Musata Kaunda-Banda in Harare’s Borrowdale Brooke area.

The Zambian government declared three days of national mourning and with a state funeral due to have been held on Sunday.

Kaunda attended a funeral service held in Harare before the body was flown to Zambia, accompanied by several Zanu PF officials including national chairman Simon Khaya Moyo, party spokesman Rugare Gumbo, and politburo members Nicholas Goche, Kumbirai Kangai, Oppah Muchinguri and Victoria Chitepo.

President Robert Mugabe was informed of Betty Kaunda’s death hours before he left for the United Nations summit in New York on Wednesday.

In a condolence message, the Zanu PF chairman said: “Our President left for New York a very disturbed man, and he thought it prudent that we accompany you with the body of our mother across the Zambezi (River).

“This burden is not an easy burden to carry; that is why we want to assist you in carrying it.”

Meanwhile, South African President Jacob Zuma said Betty Kaunda played a prominent role in hosting South African freedom fighters during the apartheid era.

In his condolence message, Zuma said: "As one of the pioneers and activists for women empowerment in post-colonial Africa, her contribution will forever be cherished by posterity."

"Our thoughts and prayers are with Former President Kaunda, his family as well as with the people of Zambia as they mourn the departure of our sister and mother, Mama Betty."