(JTA) — Moroccan police are investigating the death of two Jewish sisters in their home in the central city of Beni Mellal.

The sisters, whose names were not made public, were found earlier this week in a state of advanced decomposition and are believed to have died three months ago inside their locked home, the news site le360.ma reported Friday.

Police, who had to break down the door to enter after neighbors complained about foul smells, found the bodies of the sisters, ages 64 and 51, lying in their beds.

Each body was lying next to a plastic bowl, which police believe the sisters used because of severe vomiting. Police found no evidence of violence or robbery and deduced the sisters died of poisoning, according to the news site agadir24.info. The source of poisoning remains undetermined pending a forensic examination, the news site reported.

One of the sisters was mentally disabled, according to the report.