Applicants for visas and permits must be of good character. You may have to supply a police certificate (or similar) as evidence of good character, depending on which policy you apply under.
From 18 October 2010, the Singapore Police Force will cease to issue Certificates of No Criminal Conviction for Non-Singapore Citizens.
Non-Singapore citizen may apply for a Statutory Declaration through the Commissioners of Oath or qualified legal practitioners. You can refer to the Singapore Academy of Law website www.sal.org.sg for a list of appointed Commissioners for Oaths or you may email your queries to conp@sal.org.sg for assistance.
For non-Singapore citizens residing outside of Singapore, please enquire with the relevant authority in your country of residence on how to apply for a statutory declaration.
You can apply for a Certificate of Clearance. See the police certificate information page for Singapore, for details.