Egypt's ousted leader Hosni Mubarak was released from prison and transported by helicopter to a military hospital in Cairo today.

The medically equipped helicopter landed at the jail as dozens of his supporters rallied outside waiting for him to be released after more than two years in detention.

Private TV stations screened footage of his arrival at the hospital in a Cairo suburb where he will be held under house arrest.

The release threatens to stoke the unrest as the Arab nation is already gripped by a crisis over a military coup that ousted Mubarak's Islamist successor Mohammed Morsi.

Prime Minister Hazem el-Beblawi has ordered that Mubarak be put under house arrest as part of the emergency measures imposed this month after a wave of violence sparked by Morsi's ousting. The decision appeared designed to ease some of the criticism over Mubarak being freed from prison and ensure that he appears in court next week for a separate trial.

It was the latest development in the saga of the longtime leader, toppled in Egypt's 2011 uprising.

Even if released, Mubarak still faces retrial on charges of complicity in the killing of nearly 900 protesters in the uprising. His trial resumes next week.

TV footage showed the helicopter carrying Mubarak arrive at the pad outside the military hospital, on the banks of the Nile. He was immediately transported to an ambulance, heavily guarded, and moved across the street to the hospital. Mubarak was not seen during the transport.

Mubarak was held for several weeks of his two years detention in the same hospital as he underwent medical check-ups. His lawyers had cited bad conditions in the prison facilities. Prison authorities had renovated a ward where he was later kept.

Since his ousting, Mubarak's supporters have released conflicting details about his health, including that he suffered a stroke, a heart attack and at times went into a coma. His critics called these an attempt to gain public sympathy and court leniency.

His wife, Suzanne, has been living in Cairo and keeping a low-profile, occasionally visiting Mubarak and their two sons in prison.