Sources from the diplomatic missions in Harare say medical equipment has been installed at the president's home.
Mr. Mugabe, the oldest leader on the African continent, has hardly been seen in public or in the media since a Reuters interview last Thursday, when he claimed he was enjoying good health. Mugabe's assertion only further fueled speculation, with various websites stating that the leader recently collapsed.
"Yes, the rumors over his health could be true because we have not been seeing him of late in public," says a minister in Mugabe's coalition government, a member of the rival Movement for Democratic Change, who declined to be indentified.
On Wednesday, Mugabe's spokesman George Charamba dismissed the rumors.
"As I am talking to you right now; the president is in good, very good health," Mr. Charamba told the Monitor. "He is as fit as a British bulldog! But it is not my business to chase up on propagated rumors doing the rounds on the Internet. The truth is that the president is fit, and I am satisfied with his health."
He vehemently rejected claims that Mugabe sometimes uses a wheelchair to move around his official state residence.
But sources within the diplomatic community who spoke to the Zimbabwe Situation website and The London Times newspaper insisted that Mugabe is not healthy enough to prolong his 30-year grip on power. The sources reportedly told the media, "Mugabe is an actor who can audition as a healthy and fit man ready to rule, but his body has been patched up as many times in his private life."
In a Reuters interview last week, Mugabe dismissed such claims as baseless and untrue.
"I don't know how many times I die but nobody has ever talked about my resurrection," Reuters quoted Mugabe saying. "I suppose they don't want to, because it would mean they would mention my resurrection several times and that would be quite divine, an achievement for an individual who is not divine.
"Jesus died once, and resurrected only once, and poor Mugabe several times," he said.
"My time will come, but for now, 'no'. I am still fit enough to fight the sanctions and knock out (my opponents)," he said.
Leading contenders to take over Mugabe's presidency include Defence Minister Emmerson Mnangagwa and Solomon Mujuru, a former army chief whose wife Joice is vice president. Both are hardline members of Mugabe's Zanu PF party and have strong ties to Zimbabwe's security apparatus.
Mugabe has said that he intends to run in the presidential election that is likely to be held next year.