Illegal sex drug dealers are targeting lonely old men not only to buy their wares, but also to help smuggle supplies into Singapore.
The Health Sciences Authority (HSA) has found foreign women paying the men with cash, sex or both to have drug supplies delivered to the men's homes.
It told The Sunday Times that the women zero in on elderly men at coffee shops and chat them up, often telling them sob stories to gain sympathy and trust.
Then they ask a favour - to have some packages delivered to the men's homes, claiming they contain items for prayers or food products.
The men get paid between $150 and $500 per delivery. Some also receive sexual favours.
The HSA's deputy group director of Health Products Regulation, Associate Professor Chan Cheng Leng, said: "They target old men as they appear to be easy prey. If they are caught, the men take the fall while the women just disappear."
The HSA has investigated five such cases since it noted this modus operandi about two years ago, but Prof Chan suspects more men may have unwittingly become the peddlers' partners in crime.
Some of the men caught were clueless about the contents in the parcels delivered to their homes. Others opened the boxes and found them stuffed with sex pills.
The peddlers sent between about 450 and 23,000 pills to these men, with a street value of between $1,000 and $57,000.
In one case, a 67-year-old divorcee got to know a foreigner in her 30s at a Geylang coffee shop. Two weeks after they met, she asked to use his home address to have some "prayer materials" delivered to her. She gave the retiree $300 and had sex with him.
The man opened the parcel, found the drugs and realised what she was up to. Still, he played along.
He was arrested when the second delivery arrived. Almost 23,000 pills worth about $57,000 had been sent to his home.
He was jailed for three months last year. The woman was jailed for 10 months and fined $3,000.
Prof Chan said sex drug dealers have tried various ways to bring in their supplies over the years.
They used to ship the pills to Singapore in containers, claiming they were bringing in vases or religious artefacts.
Once the authorities caught on, they switched to getting runners to bring in small amounts of pills packed in their luggage.
Then they started the mailing ruse.
The peddlers, who are foreigners, hawk their sex pills openly in the red-light district of Geylang. Some also sell them online.
From 2010 to last year, the HSA conducted 169 raids in Geylang and seized about 2.5 million pills and products worth more than $6 million. Twenty-six people were either jailed or fined for peddling sex drugs over that period.
Those caught face up to two years in jail and/or a maximum fine of $10,000.
Sexual enhancement drugs can only be sold to those with a doctor's prescription.
When The Sunday Times visited Geylang last Thursday night, there were about 20 peddlers selling sex drugs openly outside the New Cathay Hotel at the junction of Geylang Road and Aljunied Road. Most appeared to be from China.
Each had at least a dozen brands of sexual enhancement products with names such as African Black Ant, Max Man and Viagra, as well as contraceptives.
The notorious Power 1 Walnut, which was linked to a spate of deaths in 2008, is no longer sold here, said Prof Chan.
She noted that people mistakenly believe that only Power 1 Walnut is deadly. All sex drugs sold illegally could be harmful, she stressed, as there is no telling what they contain.
Prof Chan estimated that it cost as little as one cent to produce one pill which is then sold for between $1.50 and $2.50.
Men buy the illegal drugs because the legitimate sex enhancement pills cost as much as 10 times more from a doctor.
She said: "Illegal sex drugs are potentially harmful when consumed and the HSA has been providing regular advisories to educate the public. However, due to some members of the public who are still not aware of such dangers, illegal drug peddling activities have continued to thrive."