Jeff Moran, a spokesman for the Philadelphia medical examiner, said there were no signs that Nadia Malik, 22, had died violently, the Delaware County Times reported. Moran said toxicology tests would take six to eight weeks.
Malik's body was discovered Thursday in a Nissan Altima parked near Philadelphia's main train station. It apparently had been ticketed and even towed from a snow emergency street with the body inside.
Police found bottles of prescription pills in the name of Malik's boyfriend, Bhupinder Singh, the Philadelphia Inquirer reported. Singh, who was arrested at his parents' apartment in Solon, Ohio, on probation violation charges, was awaiting extradition to Pennsylvania.
Singh has said he and Malik got into a fight, and he left her in the car alive, traveling to Ohio by bus.
Malik's family had not seen her since Feb. 9. She lived in Marple, a Philadelphia suburb.
Police said the body was covered with clothing and a duffel bag, the Times said. The car also had tinted windows and, at times, was partly buried in snow.
"You would have to be peering very, very intently in the car to think there was something in there," Marple Police Chief Thomas Murray said.
Malik and Singh had two young daughters.