Cairo (CNN) -- Hosni Mubarak, the onetime Egyptian strongman who was toppled by a popular uprising in February, has regained consciousness after lapsing into a coma Sunday, a top hospital official said.

The 83-year-old ex-ruler fell into a coma around noon (6 a.m. ET), Mubarak lawyer Farid El Deeb told CNN. Hospital officials later confirmed the report. But Mohamed Fathalla, the head of the Sharm el-Sheikh facility, told CNN that Mubarak had recovered by Sunday evening.

"He is now stable after suffering a coma that did not last long," Fathalla told CNN.

The former president faces trial in August on charges of ordering police to kill anti-government protesters during the uprising that forced him from office in February. He faces a possible death sentence if convicted.

Egyptian prosecutors have said Mubarak has suffered from depression, fatigue, repeated irregular heartbeats, low blood pressure that could lead to fainting and an increased risk of heart attack. He was hospitalized after suffering heart palpitations in April and has been struggling with complications from stomach cancer, his lawyer said.

El Deeb announced in June that Mubarak underwent cancer surgery in June 2010 at a German hospital. Parts of Mubarak's pancreas, gall bladder and a growth on his small intestines were removed during the procedure, which was kept secret even from top aides.

His doctor recommended that Mubarak receive a comprehensive follow-up every four months for two years after the operation, "But the follow-up was completely ignored," El Deeb said.

Mubarak, a longtime U.S. ally, stepped down February 11 after an 18-day uprising during which pro-democracy protesters demanded reform and a new government. Egypt is now ruled by a military council and a caretaker cabinet, which has promised reform and new elections.

The human rights group Amnesty International has estimated at least 840 people were killed and more than 6,000 wounded during the revolution, many of them suffering gunshot wounds to the head and chest. In addition, there were numerous cases of protesters being tortured following their arrests, the group reported.

El Deeb has said Mubarak is "very sad and sorry" about the allegations against him, but denies giving any kind of authorization to fire on demonstrators. In addition to charges against the former president, Mubarak's sons, Gama and Alaa, also face corruption charges.

Journalist Mohamed Fadel Fahmy contributed to this report.