Question is would you have to declare any expired convictions
Not sure about Singapore but i remember reading something about Blair allowing US authorities access to UK citizens criminal/arrest history even on stuff that was expunged or out of date for use by UK officials and law enforcement.
That is why some poor bastards when asked upon arrival at US immigration if they have ever committed a crime they answer NO due to there sole conviction either being out of date or when they were a minor being held in detention then deported because the US have access to all that data.
best policy is do not lie and tell them everything, they probably already know it anyway and are just checking to see if you are gonna fess up.
the reason they kick you out is not the crime, it is lying to them about it