A Chinese national drugged three masseuses from China with a liquid sexual-enhancement drug before stealing from them.
Production operator Feng Qidong, 35, was told the drug, which he purchased from a street peddler in Geylang, would cause unconsciousness if taken in large amounts.
On Dec 4 and 30 last year, and on Jan 4 this year, he served spiked drinks to the women with the intent to steal from them.
Yesterday , Feng was given 34 months' jail after admitting to one count of causing hurt by means of poison and two charges of theft in dwelling.
Two other charges were considered.
Deputy Public Prosecutor Jotham Tay said that on Dec 4 last year, Feng contacted Ms Li Xueying, 35, online to book her services in Lorong 30 Geylang.
He turned up at the apartment with a cup of soya bean milk that had been mixed with about half a bottle of the sexual-enhancement liquid.
After the massage, they had consensual sex.
Feng then gave her the soya milk mixture, which she drank and fell asleep shortly after. He stole $4,500 and two mobile phones totalling $800 from her, and left.
He did the same thing on Dec 30 when he went to the apartment of Ms Wang Yanmei, 39, in Lorong 39 Geylang for a massage.
She fell asleep after consuming milk tea he had given her.
About an hour later at 12.10am, he searched the apartment and stole $6,400 and a $100 phone.
In the last incident, DPP Tay said that on Jan 3, Feng took two spiked cups of soya bean milk to the Lorong 30 flat for his appointment.
He offered the drinks to Ms Zhou Mingcui, 30, and Ms Zhu Shirong, 37, but only Ms Zhu drank the soya bean milk and felt giddy.
Feng repeatedly insisted that Ms Zhou, who was massaging him, drink the soya bean milk.
Feeling something was amiss, Ms Zhou took a photograph of Feng and shared it with another Chinese national, who recognised him as the same person whom she had previously massaged.
The 26-year-old called the police, who then arrested Feng.
Ms Zhu's blood sample was found to contain Clonazepam, which causes drowsiness, dizziness, unsteadiness, difficulty in thinking or remembering, and blurred vision.