CLEVELAND (AP) -- The remains of Marilyn Sheppard's exhumed fetus have apparently degraded too much to be used in the new court battle over the case that inspired the "The Fugitive" film and TV series.

DNA results are inconclusive as to whether Dr. Sam Sheppard was the biological father of the fetus, Cuyahoga County Prosecutor William D. Mason said Monday. He said the samples had broken down.Prosecutors had ordered the exhumation to defend the state in a wrongful imprisonment lawsuit brought by the Sheppards' son, Sam Reese Sheppard, 52. They had hoped evidence that Dr. Sheppard was not the father of his wife's unborn child could be used to show a motive for murder.

The doctor was convicted of his wife's murder in 1954 and spent 10 years in prison before the U.S. Supreme Court overturned the verdict and Sheppard was acquitted at a retrial. Dr. Sheppard, who died in 1970, always claimed a bushy-haired intruder killed his wife.

The younger Sheppard has been trying for a decade to clear his father's name in his mother's violent death. Sam Reese Sheppard is suing to have his father declared innocent, a finding that could lead to Ohio being financially liable. The civil trial is scheduled for Jan. 31.

Mason said tests on the fetus showed that Sheppard could have been the father, but the information could not be confirmed.

Lawyer Terry Gilbert, who represents the younger Sheppard, would not comment before the official release of the coroner's report. But he said Sam and Marilyn Sheppard were happy about the pregnancy and that there was never any evidence of marital discord concerning it.

Sam Reese Sheppard and his lawyers believe evidence exists that a former window washer, Richard Eberling, a former Ohio prison inmate now deceased, committed the 1954 crime.

Mrs. Sheppard's body, and that of the male fetus she was carrying at the time of her death, were exhumed Oct. 5, more than 45 years after they were laid to rest in a suburban Cleveland cemetery.