Article 21 — Effect as regards setting in motion of proceedings or arrest.

(I) In the case of offences as defined in Art. 19 and 20, proceedings may be instituted without an accusation or complaint being lodged, unless the of- fence cannot be prosecuted except upon a formal complaint. 24 CRIMINAL PROCEDURE CL E (2) An arrest without warrant may in such cases be made on the conditions laid down in Art. 49 et seq.