It's a little difficult for me to check from here. -It needs someone to look underneath and narrow it down. Possibly the drain is leaking, you may have forgotten some vegetables you stored there or other similar things.
Yes, you need to look. Empty everything out and check to see if there is dampness, puddling, rotted areas, mold or slime anywhere. Clean it all up- pipes, floor, inside walls, cleanser bottles- with some kitchen spray cleaner and leave the doors open for a couple of days. You should be able to determine if something is leaking and needs to be repaired.
Your dishwasher may have a leak. Look under it with a flashlight just after it's finished a wash.
Under the kitchen sink.
A dishwasher can cause a bad smell at the kitchen sink. most of the time it is either the disposal it self, or drain tube is full of food by material, between disposal and baffle tee, or if have or had leaks could be coming from under cabinet, mold and bactieria growing
Sink strainer nut broken or loose. Putty under sink strainer rotted away.
Valves under the sink NO WORK HUH?
look under the kitchen sink if he is not there then yes :/
Try looking for them under the kitchen sink, they might be there.
plumber
under the sink waste plug hole
A simple adjustable wrench is all you need to replace the plumbing under a kitchen sink. It's a simple procedure.
If indeed it is IN your sink, simply run lots of hot soapy water through it.
Storage trayFlip try, installed on the false fronts of kitchen cabinets on the sink base. www.qualitykitchenandwindows.net/