Most items that are smuggled to Sarawak through Kalimantan usually using the land route, mostly around Tebedu and Serikin.
Usually they use trails, called 'jalan tikus', that far from the border entrance and main roads.
I knew this because my dad was a police officer and was stationed once at Serian(Tebedu in Serian district), and sometimes they caught some smugglers.
Usually they just confiscate the items and let the smuggles go, unless they smuggles dangerous things like drugs or firearm.
I'm gonna ask my local supplier if he got new stocks. The problem with him is that he only sell what item he got from the main supplier, which I suspect is from Sabah. Those from Sabah usually got their suppply from Philippines.