Was headed out to SIN a few days back on a very last minute trip due to a family emergency. I booked a one-way only as I wasn't sure of when my return would be. On check-in (6E), the agent insisted that i had to show a return ticket. So i ended up stepping aside from the lines, booking a return ticket for a few days out and then proceeding to check in again.

The agent said they had to ask for a return ticket when the passenger is travelling on a Tourist/ Visitor visa. Wondering if this is indeed the rule ? Or perhaps some airlines don't implement so strictly ?

Interestingly they were also asking all passengers who mentioned they're staying with friends/ family in Sg to show the Work Visa, PR, Sg ID card of the host.