More tests are needed to determine a cause of death of ex-model Anna Nicole Smith, the Broward County, Fla., medical examiner said Friday.

Joshua Perper said his gross exam found "no tablets or pills in her stomach," although he said he would not determine the cause or manner of Smith's death until all of the tests, including a toxicology report, were completed, which could take between three and five weeks.

Police "found no illegal drugs, only prescription medications" in the hotel room where Smith was found Thursday, Seminole, Fla., police chief Charlie Tiger said. Officers also "found no evidence revealing a crime," he said.

Smith, a reality TV star and former model, died in a hospital after being found unresponsive in her room at the Seminole Hard Rock Hotel & Casino in Hollywood, Fla.

Perper said his six-hour exam excluded physical injuries as causing or contributing to the 39-year-old's death. He noted bruising on her back, apparently the result of a fall days earlier.

"Subtle findings" were noted in Smith's heart and intestines that warrant further examination, he said. A small amount of blood was found in her stomach from going into shock before she died.