A woman who had a cosmetic injection in her buttocks at a hotel near the Philadelphia airport died early Tuesday, prompting a police investigation.

Detectives said the woman and three companions traveled from London and were staying at the Hampton Inn in southwest Philadelphia. Two of them had traveled to the city in November to have their buttocks enlarged and, on Monday, one received another injection while the other had a hip augmentation.

Detective Joseph Murray said the 20-year-old woman who had the buttocks injection later complained of chest pains and trouble breathing. Paramedics were called, and she was taken to Mercy Fitzgerald Hospital where she died. Her name was not officially released.

The results of an autopsy by the Delaware County medical examiner's office haven't been released.

Police were seeking two people involved in the cosmetic procedures. They said they believe the procedures were arranged over the Internet.

"We're not quite sure right now if that person performing that procedure is licensed or unlicensed," said Lt. John Walker of the Philadelphia police southwest detectives division. "We're still working that information right now."

Walker said investigators were also awaiting test results to determine the substance used.