The pre-recorded message was Mubarak's first public pronouncement since leaving office on February 11 [Reuters]

Egypt's public prosecutor has summoned Hosni Mubarak, the former Egyptian president, and his sons as part of investigations into the killing of protesters and the alleged embezzlement of public funds.

Mubarak's sons, Gamal and Alaa, have also been summoned in the embezzlement investigation, the prosecutor said in a statement on Sunday.

Ahmed Nazif, the country's former prime minister, has also been detained for 15 days as part of investigations into misuse of public funds, the public prosecutor's statement said.

"The phrasing of this has got to be looked at very carefully," reported Al Jazeera's Mike Hanna, in Cairo. 

"The word 'summoned' was not strictly used as a direct translation. What the prosecutor general has said is that he 'requests and requires' the deposed president and his two sons to answer questions relating to financial irregularities and also to the role that they played in the military crackdown that led to a number of deaths of protesters during Egypt's revolution."

Hanna said that while Mubarak and his sons have only so far been requested to appear for questioning, there is weight behind the statement.

"The prosecutor general has said as well that he has now notified the interior ministry of his request. This now gives this request real muscle. The assumption is that if it not obeyed or recognised, then steps could be taken to order the arrest of Mubarak and his sons."

If Mubarak's questioning is to be part of a protracted and ongoing investigation process, as it appears to be, then it remains unclear whether this will appease protesters who have called for Mubarak to be immediately arrested, Hanna said.

The prosecutor's office, meanwhile, also said that it had sequestered land belonging to Prince AlWaleed bin Talal, a Saudi billionaire. The land, in Toshka, in the south of the country, is part of a desert reclamation project, but the prosecutor did not immediately make it clear what the motivation behind the move was.

Mubarak hits out at critics

Earlier on Sunday, Mubarak, who was ousted after an 18-day popular uprising, said that he would co-operate with the country's general prosecutor during the corruption investigation, and defend himself against a campaign of "distortions, lies and incitement".

In his first public message since being forced from office on February 11, Mubarak said he felt "a lot of pain" due to the "unjust campaign" against him and his family.

"I cannot stay silent regarding the incitement campaign against me," he said in the pre-recorded audio message that was aired on Al Arabiya television on Sunday.

Mubarak said that he had given up his position as president in "the interest of the country", and that he has "decided to stay away from politics".

He said he had "waited for weeks" for the general prosecutor's office to conduct its investigations, and asserted that he did not own any assets abroad.

"I agree to submit any written letters to help the general prosecutor and foreign ministry to ask any government in the world to expose my assents abroad since I took office," he said. "I want to make sure that the Egyptian people know I only own assets in a bank account inside the country."

He said that he would submit written approval to the authorities to allow them to investigate his own and his family members' possible ownership of assets abroad.

"All the assets I own and my sons are far from any allegations of corruption," he said.

"After the legal process is complete, I reserve the right to legally pursue those who engaged in lies and distortions against me."

The message was recorded at Mubarak's residence in Sharm al Shaikh on Saturday.

Thousands of people gathered in Cairo's Tahrir Square to protest against Mubarak's remarks, with demonstrators decrying his denials of wrongdoing.