Newspapers in Egypt and Saudi Arabia, citing anonymous sources close to the former president, have reported in the last couple of days that Mubarak is seriously ill and, according to some stories, may be in a coma.
Reuters said a military source told the agency Tuesday that Mubarak was "breathing" but would not be more specific.
But the agency also reported that a source close to Mubarak said the former president was taking phone calls at his resort in the Egyptian port city of Sharm-el-Sheikh.
"He's fine," Reuters quoted the source as saying. "I spoke to him … this afternoon."
A Saudi-owned newspaper had earlier reported that Mubarak's health was "declining drastically" and that he had refused medical treatment.
Mubarak has made no public appearances since resigning last Friday after an 18-day uprising.
No appearances since resignation
The Egyptian ambassador to the U.S., Sameh Shoukry, earlier appeared to give some credence to the rumours of ill health."I am following the rumours and the press reports related to his health and might have received some communication at a personal level indicating that he is possibly in somewhat of bad health," Shoukry told NBC's Today Show on Monday.
One Egyptian paper said Mubarak fell into a coma on Saturday night. But a pro-government paper later discounted the story, reporting he was "in a severe psychological condition."
Rumours of ill health have swirled around Mubarak for a while. His gall bladder was removed last year in Germany.
There were rumours on the weekend that Mubarak had flown to Germany for treatment, but German officials denied that.