Egyptian President Hosni Mubarak's grandson died abruptly, the president's office said Tuesday, declining to give a cause of the 12-year-old boy's sudden death.

Mohammed Mubarak passed away Monday after a "health crisis lasting two days," the presidency said in a brief statement.

State media reported he was flown to Paris for emergency treatment, where he was joined by his grandmother, Egyptian first lady Suzanne Mubarak.

His body was flown back to Egypt Tuesday for burial.

Mohammed is the child of Mubarak's son Alaa, 47, a prominent businessman who is not involved in politics. Alaa has another son, Omar, who is 6 years-old.

The 81-year-old president is believed to be grooming his other son, Gamal, to succeed him.

Egyptian TV broadcast religious songs sung by children.

The northern Cairo suburb of Heliopolis, home to the president, was under heavy security presence ahead of the child's funeral which is expected to be attended by the president and top state officials.

Speculation has been rife in the Egyptian media over the cause of death, including suggestions that the boy died from a brain aneurysm, childhood leukemia or food poisoning.

Egyptians first caught a glimpse of Mohammed when he appeared in photographs with his grandfather on the pages of the leading state-owned daily Al-Ahram a decade ago. It was rare glimpse of the stern president's human side as he and his wife played with the child.

Mubarak is scheduled to visit the United States on May 26 to meet with President Obama for the first time since he assumed office.