In an official statement released by the Thabo Mbeki Foundation earlier in the day, Mbeki, his board and his staff expressed "great sadness over the passing of our leader, Isithwalandwe Ahmed Mohamed Kathrada".
Kathrada, who spent 26 years and 3 months in prison, including 18 years on the infamous Robben Island, was admitted to the hospital on March 4 initially for dehydration but doctors later picked up a clot in his brain which was subsequently removed.
Tributes poured in for Kathrada, who was released from prison in October 1989 at the age of 60.
Ahmed Kathrada, a veteran anti-apartheid activist and contemporary of Nelson Mandela, has died.
Kathrada, who was a lifelong supporter of the African National Congress (ANC), Palestine and all things liberation-related, was sentenced to life imprisonment along with the Mandela.
"Comrade Kathy was a gentle, humane and humble soul".
Archbishop Emeritus Desmond Tutu has described his late friend Ahmed Kathrada as a person of the highest integrity who was a blessing for all South Africans.
His fellow prisoners included Mandela, Walter Sisulu and Denis Goldberg.
Be proactive - Use the "Flag as Inappropriate" link at the upper right corner of each comment to let us know of abusive posts. It was a lesson he took personally, earning four university degrees through correspondence - in history, criminology, African politics and library science, two of them honors degrees. Kathrada, who has known Madiba for 64 years, was joined by activist turned businessman Cyril Ramaphosa, not pictured, who is also the chairperson of the Ahmed Kathrada Foundation. We are shattered by his death but Kathrada will be remembered for his role in creating a new and vibrant South Africa.
"He was a comrade, associate and close friend of Nelson Mandela's through seven decades", Ndebele said in a statement.
Deputy President Cyril Ramaphosa visited Kathrada's wife, Barbara Hoganâ€Ü at their home in Johannesburg to personally pass condolences to the family on behalf of the Government. He was also one of the most senior ANC leaders to criticize President Jacob Zuma's presidency regarding allegations of government corruption and maladministration.
Former Robben Island and Pollsmoor Prison warder for Kathrada, Christo Brand, says the struggle icon was like a father to him.
The foundation said Kathrada's ideals were yet to be realised.