Hosny Mubarak was recovering in hospital Wednesday after reportedly suffering from a heart attack while under interrogation, doctors in Egypt said, DPA reported.
Mubarak was in a stable condition in the presidential suite at the main hospital of the Red Sea resort of Sharm el-Sheikh, a doctor who declined to be named told the German Press Agency dpa.
Sources said the former president was later expected to be moved to a military hospital in Cairo following an order for his arrest by Egypt's state prosecutor.
He is to be detained for 15 days while an investigation into corruption and abuse of power charges is conducted, officials said.
State television reported that the 82-year-old had suffered a heart attack during a first round of questioning by authorities Tuesday.
Concerns over his medical state were reportedly the reason given for not detaining Mubarak yet.
Until Tuesday, he had been under house arrest at his sprawling compound in Sharm el-Sheikh.
Security sources in South Sinai told dpa that he underwent a new round of questioning after being admitted to hospital.
Witnesses said some 300 people took part in a protest outside the hospital, where Mubarak was reportedly seen walking around.
Prosecutors also ordered the detention of Mubarak's sons Gamal and Alaa for questioning over their alleged role in attacks on anti- government protesters that left over 800 dead earlier this year.
Security sources said the two were taken Wednesday to Tora prison on the outskirts of Cairo, where other former government officials have been detained.
Mubarak's wife Suzanne has also been placed under investigation for allegedly pocketing state funds, according to the state-ran al-Ahram Portal.
The website reported that Egypt's former first lady was being probed in connection with the multi-million dollar funding of the Bibliotheca Alexandrina, the country's famed library.
Mubarak, who had been in power for nearly 30 years, stepped down on February 11 following an 18-day uprising across the country.