Egypt's state prosecutor on Thursday ordered imprisoned former dictator Hosni Mubarak transferred to a military hospital after his health deteriorated, a source at the prosecutor's office said.

Mubarak, serving a life sentence over the killings of protesters, was briefly taken to hospital on December 19 for scans after he fell in his prison bathroom and hurt his head.

Mubarak, 84, will be returned to prison after he is treated, the source said.

A court sentenced the veteran strongman to life in June for failing to prevent the killings of protesters during the 18-day revolt that ended his three-decade rule in February 2011. Some 850 people died in the uprising.

Since his fall from power, Mubarak's health has appeared to deteriorate significantly, and he has suffered repeated health scares.

He spent nearly a month in hospital after he fell unconscious on June 19, with state media declaring him clinically dead on arrival. Medical sources however said he appeared to have fallen into a temporary coma.

During his time in power, the subject of his health was very much off-limits.

In 2004, he underwent surgery in Germany for a slipped disc, and he returned to Germany in March 2010 for the removal of his gall bladder and a growth on the small intestine.

During his time in power, he survived 10 attempts on his life.