COLCHESTER - The 98-year-old woman whose body was found in her son's freezer in this Delaware County town died of cardiac arrest, state police said on Saturday.

The body of Herta Auslander was discovered in a chest freezer at the home of her 70-year-old son, Ronald, on Wednesday after state police were notified about the remains by the son's attorney. The lawyer told police the elderly woman died 18 months earlier, in April 2007.

Police said the woman was born on Aug. 19, 1908, meaning she was 98 at the time of her death if the lawyer's account is accurate.

Police said on Friday that they did not suspect foul play in the woman's death. On Saturday, they said an autopsy, performed at Lourdes Hospital in Binghamton, confirmed she died of natural causes, specifically heart failure.

The autopsy was performed by forensic pathologist Dr. James Terzian, police said.

Police said they are continuing to investigate why Ronald Auslander put his mother's remains in the freezer and why her death went unreported for so long, though it appears money was the motive. The son continued to collect and cash his mother's Social Security checks after she died, endorsing the documents with a rubber stamp bearing the woman's signature, police said.

State police Lt. James Barnes said the son is cooperating with authroities and that no charges against had been filed against him as of Saturday afternoon.