CAIRO — Egypt's ex-president Hosni Mubarak, detained pending a probe into corruption and state violence, may be jailed or hanged if found guilty of ordering the killing of demonstrators, state media said on Friday.

The state-owned newspaper Al-Ahram quoted the head of Cairo's appeals court, Zakaria Shalash, as saying that Mubarak may face execution after a trial he expected to last at least a year.

Mubarak and his two sons Alaa and Gamal were remanded into 15 days custody this week after prosecutors launched a probe into violence against protesters during an 18-day popular uprising that forced Mubarak to resign on February 11.

A corruption panel will begin questioning them next week on suspicion of graft, the newspaper reported.

Shalash said the testimony by Mubarak's former interior minister Habib al-Adly, who himself is on trial on charges of ordering the shootings of anti-regime protesters, made Mubarak an accomplice if proven.

Adly said he was ordered to use violence against protesters by the former leader.

"If proven, he (Mubarak) will receive the same punishment as the person who carried it out and it could reach execution if it is proven that peaceful demonstrators were killed with premeditation," he said.

Mubarak may receive life if shown there was no premeditation in the deaths of the protesters, he added.

An estimated 800 people were killed in protests that toppled the veteran leader.

Mubarak may also be sentenced to three to five years if it was proved that violence he ordered maimed protesters, Shalash said.

None of the suspicions that led to Mubarak's detention have so far translated into charges.

He is in a hospital under police guard after suffering a heart attack and his sons are being held in a Cairo prison.

The investigation itself may last six months, state television has reported, citing a prosecution official.

Shalash added that the Mubaraks may face between three to 15 years if suspicions of graft and corruption were established.

Mubarak's trial was a key demand in protests that attracted tens of thousands in the past weeks, eventually leading to a deadly clash with soldiers who tried to disperse an overnight demonstration in Cairo.

Opposition groups suspended a planned demonstration on Friday after the former president and his sons were detained.