The child could inherit millions in the long-running court battle over her mother's former billionaire husband. A judge has ordered that Ms Smith's body be preserved until a paternity hearing later this month.

An initial post-mortem examination had failed to find what caused the former model's death on Thursday.

But medical examiner Joseph Perper said he had not ruled out an overdose as a cause, and was waiting for the results of chemical analysis.

There was "no evidence" to suggest that Smith's death was the result of a crime, a police spokesman said, adding that the inquiry would remain open until medical tests were complete.

Smith died only five months after the birth of her daughter, Dannielynn.