An Israeli newspaper says Prime Minister Ariel Sharon's health problems were far more serious than his doctors publicly acknowledged after he suffered a first stroke last month

Doctors treating Mr. Sharon after the December 18 stroke said he had a small hole in his heart since birth. He was scheduled to undergo a surgical procedure this month to repair the defect but suffered a massive second stroke the day before.

The Haaretz newspaper says its own investigation revealed that Mr. Sharon also suffered from a large aneurysm in the septum - a condition known to be a source of cerebral blood clots. The report says he also suffered from other heart ailments.

The 77-year-old Israeli leader remains comatose in a Jerusalem hospital since suffering a massive brain hemorrhage on January 4.

Some information for this report was provided by AFP and AP.