Johannesburg:
A series of tweets mistakenly announced that Nelson Mandela was hospitalised on Friday after a local television channel showed archive footage of his January illness in a review of 2011.
South Africa's presidency had to issue an assurance of Mr Mandela's good health at his rural homestead to quell the rumours.
"Former President Nelson Mandela is in good health, good spirits and enjoying the festive season at his home in Qunu," presidential spokesman Mac Maharaj said in a statement. "The Presidency has received calls from the media enquiring about Madiba's health," he said, using Mandela's clan name.
"It appears that an end of year review done by a media house may have unfortunately triggered a rumour of ill-health."
The Nelson Mandela Foundation, which guards the anti-apartheid struggle icon's legacy, also denied the rumours.
The eNews channel today broadcast images of Mr Mandela's hospitalisation for an acute respiratory infection in January, as part of an overview of the past year's news events.
This sparked a series of alarmist posts on the micro-blogging site Twitter, picked up even by foreign affairs spokesman Clayson Monyela.
Monyela later removed his tweet "Pray for Tata", which referred to Mandela with a term of respect. Following his release from hospital, Mr Mandela settled at his rural home in the Eastern Cape province 800 kilometers from Johannesburg.
The frail 93-year-old's health has sparked intense national and international media attention. Rumours over his health periodically flare up on social networking sites.
Mr Mandela was elected the country's first black president in South Africa's first all-race vote in 1994 and served one term before stepping down in 1999.