Delaware authorities are reportedly investigating the death of Linda Stevenson, the wife of Jill Biden's first husband, Bill Stevenson, after police responded to a reported domestic dispute at the couple's home late Sunday night.

New Castle County Police said officers were called to a residence in Oak Hill around 11:15 p.m., where they found Linda Stevenson, 64, unresponsive in the living room, TMZ reported Tuesday. Officers administered life-saving measures, but she was pronounced dead at the scene.

Police confirmed the case is being handled by the department's Criminal Investigations Unit.

No charges have been filed, and Stevenson's body has been sent to the Delaware Division of Forensic Science for an autopsy to determine the cause and manner of death.

Dispatch audio from the incident referenced a possible cardiac arrest.

Bill Stevenson was married to Jill Biden in the early 1970s before their divorce.

She later married Joe Biden in 1977, during his tenure as a U.S. senator.

The investigation remains ongoing.