The cause of death of a Petaluma woman and a San Jose woman, found Sunday in a San Jose motel, remained under investigation Wednesday by the Santa Clara Medical Examiner-Coroner’s Office.

The women have been identified as Michelle Williams, 18, of Petaluma and Juliecel Aguja, 26, of San Jose, according to a coroner’s official.

The two women were found Sunday afternoon on a bed in an EZ-8 motel in north San Jose.

They’d arrived at the motel Aug. 4. A “do not disturb” sign had been on their door for days and a motel employee who went into the room made the gruesome discovery, according to South Bay news accounts.

San Jose police initially investigated, but with no clear cause of death or signs of foul play, the case was turned over to the coroner’s office for autopsies and to determine how they died, said Officer Albert Morales, a police spokesman.

Morales on Wednesday also said police detectives are awaiting the cause of death to determine if the case requires further investigation.

Toxicology tests could take months to be returned, according to a spokeswoman at the coroner’s office Wednesday.

Morales declined to release further details of the case, referring questions to the coroner’s office, which also declined to release information while the case remained under investigation.