Jerusalem ? Medical experts warned Monday that former Israeli Prime Minister Ariel Sharon’s deteriorating condition could put his life in danger, while the hospital treating him said it would run more tests to find the cause of his downturn.

The Sheba Medical Center near Tel Aviv said Sunday the former leader’s kidneys were failing and that changes were detected in his brain membrane. Sharon, 78, has been in a coma since suffering a severe stroke in January.

A hospital spokeswoman refused to say whether his life was threatened.

But two of Sharon’s former aides, who said they spoke to his son, Gilad, said Sunday there was no immediate danger to the former leader’s life.

But Dr. John Martin, a cardiovascular expert at London’s University College, said the kidney failure and the changes in the brain membrane that Sharon suffered in the past two days indicated the former leader’s life was in danger. His comments were echoed by other physicians quoted in Israeli media.