They were found naked and lying by the window in a MGM Cotai hotel room with bruise marks on their necks.

Preliminary investigations suggested the duo was a prostitute and a member of a 'money exchange gang'. They were being killed for money instead of personal grudges.

It was understood that the two had suddenly disappeared, and were being searched by their friends.

The room where they were found was not registered under their names. The hotel's security tape showed that they entered the room more than 10 hours apart.

It was suspected that the prostitute came to the room first to provide sex service to the murderer. And the murderer then contacted the other engaging in illegal money exchange later.

There was no sign of a physical fight at the scene. After a preliminary investigation, police suspected the murderer strangled the two to death with a bathrobe tie.

Officers also suspected the murderer cleaned up the scene after the attack as they have yet find any belongings or identity documents of the two women.