Sources close to the investigation said Samantha Wann was sexually assaulted before she drowned Sunday in a 4-foot deep, above-ground pool.

Investigators were awaiting results of toxicology tests on Samantha.

Michael Wann, 34, of Camden was charged with child endangerment for leaving his daughter unsupervised while he smoked the hallucinogen PCP, Camden County Prosecutor Lee Solomon said.

The host couple who police said had a dungeon in the house filled with whips, chains, leather masks, costumes, a coffin and pornographic videos also face charges of child endangerment and witness tampering.

Prosecutors acknowledged that autopsy findings prompted them to launch a wider investigation into the drowning, but declined to be more specific about whether the girl had been sexually assaulted.

"We're not saying anything on that," said Greg Reinert, a prosecutor's spokesman.

Samantha had been playing with a 7-year-old girl at the party, investigators said. It wasn't known how long she had been left unsupervised. She was found fully clothed at the bottom of the pool. Neighbors tried to resuscitate her, but she was pronounced dead at a hospital.

At least eight adults attended the party at the home of Martin Hunsinger, 51, who also was charged with child endangerment.

Hunsinger's girlfriend, Dorina D. Pizio, 47, was charged with witness tampering for allegedly trying to persuade the 7-year-old not to cooperate with police.

Prosecutors declined to say whether the older child was related to any of the partygoers. The girl was placed in protective custody by the state.

The couple were known in the neighborhood for their penchant for sadomasochism and an adult business run by Pizio, who has identified herself as a dominatrix and calls herself "Mistress Christianna."

Hunsinger listed his occupation on police records as "dungeon master."

Investigators removed a truckload of furniture from the house and sex paraphernalia typically used in sadomasochism. Solomon said the items were being analyzed.