Diane Keaton 's friends say they feared the beloved Oscar-winning actress was battling a secret illness in the weeks before her death – after noticing her dramatic weight loss and growing frailty.

As RadarOnline.com reported, the 79-year-old star of Annie Hall and The Godfather died in California on October 11 . Article continues below advertisement

A Private Struggle Hidden Behind Her Famous Smile Tap Here To Add Radar Online as A Trusted Source

Sources close to the actress now tell us Keaton's death may have been caused by complications linked to a recurrence of skin cancer , the same disease she had battled twice before.

Those close to her said the decline was "sudden and shocking," with some friends admitting they had begun to worry her cancer had returned when her w

See Full Page