I've checked for leaks, but I still smell gas in the kitchen. Any ideas what it could be?

Every time we walk into our kitchen, there is a faint smell of gas. I checked the connections on the hoses with soapy water etc… All was OK. My wife called out the local gas company, and they came out with their wands and checked everything. Again they found nothing, but the smell persists. I have checked the knobs,making sure that they are turned off properly (which they are) but can still smell the gas. Can somebody offer any other suggestions as to the cause of this. Thank you in advance for your help.