A West Chester man who was accused of torturing his girlfriend’s daughter, leaving her with life-threatening injuries, died of sudden irregular heartbeat while in jail, the Chester County coroner said Friday.

Dimitrios Moscharis, 34, was found dead inside his cell in June, seven months after he was charged with attempted murder, strangulation, aggravated assault, and related crimes for assaulting the 9-year-old girl to the point where she suffered organ damage and had to be rushed to a local hospital.

Chester County Coroner Christina VandePol said Friday that after months of investigation, her office determined that Moscharis’ cardiac issue was from natural causes, aggravated by an enlarged heart.

In detailing Moscharis’ arrest last year, county prosecutors said his behavior, which included beating the girl, locking her in a closet for hours at a time, and forcing her to sleep in a basement, was tantamount to torture.

» READ MORE: West Chester man severely beat a 9-year-old, leaving her with near fatal injuries, DA says

Moscharis was dating the girl’s mother, Julieanne Lewis, at the time, and lived with them, according to police. Lewis, 32, pleaded guilty to aggravated assault in August, and is awaiting sentencing.

Moscharis attacked the girl under the guise of discipline, he told investigators. The girl, who now lives with foster parents in another state, has since made a full recovery.