Former President Mwai Kibaki was on Sunday flown to South Africa for specialised treatment shortly after being admitted to a Nairobi hospital.
Kibaki was admitted at the Karen Hospital in Nairobi on Sunday morning after complaining of unspecified ill health.
His family in a statement posted on President Uhuru Kenyatta's Facebook page said Kenya's third president would receive specialised treatment at the South African country.
The family however, did not disclose the heath facility where the former Head of State would be admitted to.
The state of his health by the time of departure from the country also remained unknown as the family did not avail details.
"Earlier today (Sunday), His Excellency Mwai Kibaki, third President of the Republic (of Kenya), flew to South Africa for specialised medical treatment, after being taken ill," the statement read in part.
"We ask Kenyans to pray for him, and to respect the privacy of the family at this difficult time."
Kibaki is accompanied by his doctor, the statement further said.
"We expect him to return soon, and Kenyans will be informed of his progress as appropriate."
Earlier on Sunday a family source claimed he suffered a stroke.
Kibaki took over power as Kenya's Commander in Chief in 2002 after emerging top during the election that pitted him against current President Uhuru Kenyatta.
He controversially won the 2007 poll which culminated to the Post-Election Violence that claimed over 1,300 lives after ODM party leader Raila Odinga contested the presidential results as declared by the Electoral Commission.
He vacated State House after the 2013 general election and retired to his Muthaiga home in Nairobi.
His hospitalisation comes four months after the death of his wife, former First Lady Lucy Kibaki.